Hybrid driving unit and vehicle carrying the same

ABSTRACT

A hybrid driving unit in which a first electric motor ( 20 ), a second electric motor ( 23 ), a transmission ( 22 ) and a power splitting planetary gear ( 21 ) are disposed in order from the front side (the side of an internal combustion engine) on an axis within a casing member ( 14 ). Since the first electric motor ( 20 ) and the second electric motor ( 23 ) are disposed adjacently to each other, partial cases for storing these first and second electric motors ( 20 ) and ( 23 ) may be combined, thus facilitating the accommodation for producing the unit in series.

TECHNICAL FIELD

The present invention relates to a vehicular hybrid driving unit and avehicle carrying the same and more specifically to a layout of twoelectric motors, a power splitting planetary gear and a transmissiondisposed within a casing member.

BACKGROUND ART

Hitherto, there has been known a so-called mechanical power splitting(split type or two-motor type) hybrid driving unit, to be mounted to avehicle, in which an engine, a generator (second electric motor) and adriving (assist) electric motor (second electric motor) are connectedrespectively to three elements of a planetary gear unit, the secondelectric motor is coupled with an output shaft, output torque of theabove-mentioned planetary gear unit is continuously controlled throughcontrol of the first electric motor, and torque of the second electricmotor is combined with the output torque of the planetary gear to beoutputted to the output shaft as necessary.

The hybrid driving unit described above is disclosed, for instance, inJapanese Patent Laid-Open No. Hei.08-183347 as a unit for an FF(front-engine and front-drive) type vehicle and in Japanese PatentLaid-Open No. 2002-225578 as a unit provided with a transmission betweenan electric motor and an output shaft.

By the way, the position and direction of the hybrid driving unit to bemounted and the shape of the casing member will differ from those of theFF type vehicle in mounting such unit to an FR (front-engine andrear-drive) vehicle.

In case of the FR type vehicle, an internal combustion engine, a hybriddriving unit and a propeller shaft are disposed in line in order fromthe front side in the longitudinal direction of a body. That is, acrankshaft of the engine, input and output shafts of the hybrid drivingunit and the propeller shaft are disposed almost in one and same axialline. In the hybrid driving unit, a first electric motor, a secondelectric motor, a power splitting planetary gear and a transmission areaxially stored within the casing member and a plurality of partial casesdivided in the longitudinal direction of the casing member to improvethe assembility of those devices need to be jointed.

Meanwhile, taking the production of the hybrid driving unit in seriesand the mountability thereof to a body into consideration, it ispreferable to dispose the two electric motors adequately correspondingto the specification of the vehicle to which the hybrid driving unit ismounted and of the internal combustion engine to which it is combinedfrom the aspect of the cost performance.

However, because the casing member is divided into the plurality ofparts in the hybrid driving unit described above, there is a case ofcausing a misalignment of the axial center of the casing member.Thereby, the accuracy for supporting rotors of the first and secondelectric motors may drop, possibly causing vibration due to swirling ofthe axis. Still more, because the first and second electric motors arestored in the different parts of the case, respectively, it is necessaryto provide new casing members corresponding to the two electric motors.Accordingly, it has been disadvantageous for producing theabove-mentioned hybrid driving unit in series in accommodating the unitto the FR type vehicle.

DISCLOSURE OF INVENTION

It is therefore an object of the invention to provide a hybrid drivingunit, and a vehicle carrying the same, solving the aforementionedproblems by disposing first and second electric motors adjacently toeach other.

According to a first aspect of the invention, a hybrid driving unit (7A,7B) comprises:

an input shaft (10) for inputting motive power from an internalcombustion engine (5);

an output shaft (12) disposed on an axis (13) in line with the inputshaft (10) and interlocked with driving wheels (3);

a first electric motor (20) disposed on the axis (13) and having astator and a rotor (25);

a power splitting planetary gear (21) disposed on the axis (13) andhaving a first rotary element (R0) coupled with the input shaft (10), asecond rotary element (S0) coupled with the rotor (25) of the firstelectric motor (20) and a third rotary element (CR0) coupled with theoutput shaft (12);

a second electric motor (23) disposed on the axis (13) and having astator (28) and a rotor (29); and

a transmission (22) disposed on the axis (13) and shifting andtransmitting revolution of the rotor (29) of the second electric motor(23) to the output shaft (12); and

the hybrid driving unit (7A, 7B) being characterized in that:

the first electric motor (20), the power splitting planetary gear (21),the second electric motor (23) and the transmission (22) are stored in acasing member (14) while being disposed in line on the axis (13);

the stators (24 and 28) of the first and second electric motors (20 and23) are fixed to the casing member (14); and

the first electric motor (20), the power splitting planetary gear (21),the second electric motor (23) and the transmission (22) are disposed onthe axis (13) so that the first electric motor (20) and the secondelectric motor (23) adjoin each other on the axis (13).

According to a second aspect of the invention, the hybrid driving unit(7A, 7B) is characterized in that the casing member (14) is built byconnecting a plurality of partial cases in a body in the axial directionand the first and second electric motors (20, 23) are stored in one ofthe partial cases.

According to a third aspect of the invention, the hybrid driving unit(7A, 7B) is characterized in that the casing member (14) has a jointsection (H) of the partial cases (14A, 14B) at the part where thetransmission (22) and the power splitting planetary gear (21) arestored.

According to a fourth aspect of the invention, the hybrid driving unit(7A) is characterized in that the partial case (14A) storing the firstand second electric motors (20, 23) is divided into a front part closeto the internal combustion engine (5) and to a rear part by a partition(supporting member B) and the radial size of a motor storage section(14A1) of the front part is larger than that of a motor storage section(14A2) of the rear part.

According to a fifth aspect of the invention, the hybrid driving unit(7A) is characterized in that partitions (supporting members A, B and C)extending from the casing member (14) support the both sides of therotors (25, 29) of the first and second electric motors (20, 23) throughan intermediary of bearing members (a, b, f and g) and the partition (B)between the first electric motor (20) and the second electric motor (23)is utilized in common and has bearing members (b, h) supporting therotors (25, 29) of the first and second electric motors (20, 23),respectively.

According to a sixth aspect of the invention, the hybrid driving unit(7A, 7B) is characterized in that the input shaft (10) is supported bythe inner peripheral face of the rotor (25) of the first electric motor(20) through an intermediary of bearing members (c, d) provided on theouter peripheral face of the input shaft (10).

According to a seventh aspect of the invention (see FIGS. 2 through 6for example), the hybrid driving unit (7A) is characterized in that thefirst electric motor (20), the second electric motor (23), thetransmission (22) and the power splitting planetary gear (21) aredisposed in order from the side closer to the internal combustion engine(5).

According to an eighth aspect of the invention (see FIG. 2 for example),the hybrid driving unit (7A) is characterized in that the input shaft(10) is coupled with the first rotary element (R0) through the innerperiphery of the first electric motor (20), the second electric motor(23) and the transmission (22), and the output element (CR1) of thetransmission (22) is coupled with the output shaft (12) through theouter periphery of the power splitting planetary gear (21).

According to an ninth aspect of the invention (see FIG. 2 for example),the hybrid driving unit (7A) is characterized in that the powersplitting planetary gear (21) is composed of a single pinion planetarygear; the input shaft (10) is coupled with the rear side of a carrier(CR0) of the single pinion planetary gear through the inner periphery ofthe power splitting planetary gear (21); the output shaft (12) iscoupled with the output element (CR1) of the transmission (22) via aring gear (R0) of the single pinion planetary gear; and the rotor (25)of the first electric motor (20) is coupled with a sun gear (S0) of thesingle pinion planetary gear through the inner periphery of the secondelectric motor (23) and the transmission (22).

According to a tenth aspect of the invention (see FIG. 4 for example),the hybrid driving unit (7A) is characterized in that the powersplitting planetary gear (21) is composed of the single pinion planetarygear; the input shaft (10) is coupled with the transmission side of thecarrier (CR0) of the single pinion planetary gear; the output shaft (12)is coupled with the sun gear (S0) of the single pinion planetary gearand with the output element (CR1) of the transmission (22) through theouter periphery of the power splitting planetary gear (21); and therotor (25) of the first electric motor (20) is coupled with the ringgear (R0) of the single pinion planetary gear through the innerperiphery of the second electric motor (23) and the transmission (22).

According to an eleventh aspect of the invention (see FIG. 5 forexample), the hybrid driving unit (7A) is characterized in that thepower splitting planetary gear (21) is composed of a double pinionplanetary gear; the input shaft (10) is coupled with a ring gear (R0) ofthe double pinion planetary gear through the rear side of the powersplitting planetary gear (21); the output shaft (12) is coupled with thetransmission side of a carrier (CR0) of the double pinion planetary gearthrough the outer periphery of the power splitting planetary gear (21)and with the output element (CR1) of the transmission (22); and therotor (25) of the first electric motor (20) is coupled with a sun gear(S0) of the double pinion planetary gear through the inner periphery ofthe second electric motor (23) and the transmission (22).

According to a twelfth aspect of the invention (see FIG. 6 for example),the hybrid driving unit (7A) is characterized in that the powersplitting planetary gear (21) is composed of the double pinion planetarygear; the input shaft (10) is coupled with the ring gear (R0) of thedouble pinion planetary gear through the rear side of the powersplitting planetary gear (21); the output shaft (12) is coupled with thesun gear (S0) of the double pinion planetary gear and with the outputelement (CR1) of the transmission (22) through the outer periphery ofthe power splitting planetary gear (21) and between the power splittingplanetary gear (21) and the transmission (22); and the rotor (25) of thefirst electric motor (20) is coupled with the rear side of the carrier(CR0) of the double pinion planetary gear through the inner periphery ofthe second electric motor (23) and the transmission (22).

According to a thirteenth aspect of the invention (see FIGS. 7 through11 for example), the hybrid driving unit (7B) is characterized in thatthe first electric motor (20), the second electric motor (23), the powersplitting planetary gear (21) and the transmission (22) are disposed inorder from the side closer to the internal combustion engine (5).

According to a fourteenth aspect of the invention (see FIG. 7 forexample), the hybrid driving unit (7B) is characterized in that theinput shaft (10) is coupled with the first rotary element (CR0) throughthe inner periphery of the first electric motor (20) and the secondelectric motor (23); the rotor (29) of the second electric motor (23) iscoupled with the transmission (22) through the outer periphery of thepower splitting planetary gear (21); and the output shaft (12) iscoupled with the output element (CR1) of the transmission (22) and withthe third rotary element (R0) through the inner periphery of thetransmission (22).

According to a fifteenth aspect of the invention (see FIG. 7 forexample), the hybrid driving unit (7B) is characterized in that thepower splitting planetary gear (21) is composed of a single pinionplanetary gear; the input shaft (10) is coupled with the transmissionside of the carrier (CR0) of the single pinion planetary gear throughthe inner periphery of the power splitting planetary gear (21); theoutput shaft (12) is coupled with the output element (CR1) of thetransmission (22) and with the ring gear (R0) of the single pinionplanetary gear through between the power splitting planetary gear (21)and the transmission (22); the,rotor (25) of the first electric motor(20) is coupled with the sun gear (S0) of the single pinion planetarygear through the inner periphery of the second electric motor (23); andthe rotor (29) of the second electric motor (23) is coupled with aninput element (S1) of the transmission (22) through the outer peripheryof the power splitting planetary gear (21).

According to a sixteenth aspect of the invention (see FIG. 9 forexample), the hybrid driving unit (7B) is characterized in that thepower splitting planetary gear (21) is composed of a single pinionplanetary gear; the input shaft (10) is coupled with the second electricmotor side of the carrier (CR0) of the single pinion planetary gear; theoutput shaft (12) is coupled with the output element (CR1) of thetransmission (22) and with the sun gear (S0) of the single pinionplanetary gear; the rotor (25) of the first electric motor (20) iscoupled with the ring gear (R0) of the single pinion planetary gearthrough between the second electric motor (23) and the power splittingplanetary gear (21); and the rotor (29) of the second electric motor(23) is coupled with the input element (S1) of the transmission (22)through the outer periphery of the power splitting planetary gear (21).

According to a seventeenth aspect of the invention (see FIG. 10 forexample), the hybrid driving unit (7B) is characterized in that thepower splitting planetary gear (21) is composed of a double pinionplanetary gear; the input shaft (10) is coupled with the ring gear (R0)of the double pinion planetary gear through between the power splittingplanetary gear (21) and the transmission (22); the output shaft (12) iscoupled with the output element (CR1) of the transmission (22) and withthe sun gear (S0) of the double pinion planetary gear through betweenthe power splitting planetary gear (21) and the transmission (22),through the outer periphery of the power splitting planetary gear (21)and through between the power splitting planetary gear (21) and thesecond electric motor (23); the rotor (25) of the first electric motor(20) is coupled with the transmission (22) side of the carrier (CR0) ofthe double pinion planetary gear through the inner peripheral side ofthe second electric motor (23) and through between the power splittingplanetary gear (21) and the transmission (22); and the rotor (29) of thesecond electric motor (23) is coupled with the input element (S1) of thetransmission (22) through the outer periphery of the power splittingplanetary gear (21).

According to an eighteenth aspect of the invention (see FIG. 11 forexample), the hybrid driving unit (7B) is characterized in that thepower splitting planetary gear (21) is composed of a double pinionplanetary gear; the input shaft (10) is coupled with the carrier (CR0)of the double pinion planetary gear through between the power splittingplanetary gear (21) and the transmission (22); the output shaft (12) iscoupled with the output element (CR1) of the transmission (22) and withthe ring gear (R0) of the double pinion planetary gear through betweenthe power splitting planetary gear (21) and the transmission (22); therotor (25) of the first electric motor (20) is coupled with the sun gear(S0) of the double pinion planetary gear through the inner peripheralside of the second electric motor (23); and the rotor (29) of the secondelectric motor (23) is coupled with the input element (S1) of thetransmission (22) through the outer peripheral side of the powersplitting planetary gear (21).

According to a nineteenth aspect of the invention, the hybrid drivingunit (7A, 7B) is characterized in that the transmission (22) has aplanetary gear unit (27).

According to a 20-th aspect of the invention, the hybrid driving unit(7A, 7B) is characterized in that the transmission (22) has at leastfour shifting elements (S1, S2, R1, CR1), the first shifting element(S1) is coupled with the rotor (29) of the second electric motor (23),the second shifting element (CR1) is coupled with the output shaft (12),and the transmission (22) has braking elements (B1 and B2) which arecapable of fixing the third and fourth shifting elements (R1 and S2) tothe casing member (14), respectively.

According to a 21-st aspect of the invention, the hybrid driving unit(7A, 7B) is characterized in that the planetary gear of the transmission(22) is composed of a Ravigneaux type planetary gear and a carrier (CR1)of the Ravigneaux type planetary gear is coupled with the output shaft(12).

According to a 22-nd aspect of the invention (see FIG. 12 for example),the hybrid driving unit (7C) is characterized in that the powersplitting planetary gear (21), the first electric motor (20), the secondelectric motor (23) and the transmission (22) are disposed in order fromthe side closer to the internal combustion engine (5).

According to a 23-rd aspect of the invention, the hybrid driving unit ischaracterized in that the input shaft (10) is coupled with the firstrotary element (R0), and the output element (CR1) of the transmission(22) is coupled with the output shaft (12) disposed through the innerperiphery of the power splitting planetary gear (21), the first electricmotor (20), the second electric motor (23) and the transmission (22).

According to a 24-th aspect of the invention (see FIG. 13 for example),the hybrid driving unit (7D) is characterized in that the transmission(22), the second electric motor (23), the first electric motor (20) andthe power splitting planetary gear (21) are disposed in order from theside closer to the internal combustion engine (5).

According to a 25-th aspect of the invention, the hybrid driving unit(7D) is characterized in that the input shaft (10) is coupled with thefirst rotary element (R0) through the inner peripheral side of thetransmission (22), the second electric motor (23), the first electricmotor (20) and the power splitting planetary gear (21), and the outputelement (CR1) of the transmission (22) is coupled with the output shaft(12) through between the input shaft (10) and the inner periphery of thetransmission (22), the second electric motor (23), the first electricmotor (20) and the power splitting planetary gear (21).

According to a 26-th aspect of the invention, a vehicle (1) comprisingan internal combustion engine (5), hybrid driving means and rear wheels(3) as driving wheels to which driving force is transmitted from thehybrid driving means is characterized in that the hybrid driving meansis the hybrid driving unit (7A, 7B) described in anyone of the first to25-th aspects of the invention in which the input shaft (10) is coupledwith an output shaft (6) of the internal combustion engine (5), apropeller shaft (16) is coupled with the output shaft (6), and theoutput shaft (6) of the internal combustion engine, the input shaft(10), the output shaft (12) and the propeller shaft (16) are disposedapproximately on one and same axis.

It is noted that the reference characters within the parenthesesdescribed above are cited for the purpose of collating with the drawingsand do not by any means affect the composition of the claims.

According to the first aspect of the invention, since the first electricmotor and the second electric motor are disposed adjacently to eachother on the axis, the first and second electric motors may be storedwithin one member (a partial case described later), thus facilitatingthe accommodation to producing the unit in series.

According to the second aspect of the invention, since the first andsecond electric motors may be stored in a body in one partial case, anumber of parts and hence the cost of the unit may be reduced. It alsoenables to improve the accuracy for supporting the first and secondelectric motors. Still more, it enables the length of power cables ofthe first and second electric motors to be almost equalized regardlessof the position of a controller for controlling them.

According to the third aspect of the invention, since the casing memberis divided at the part where the transmission and the power splittingplanetary gear are stored, the transmission and the power splittingplanetary gear may be readily assembled while storing the first andsecond electric motors in one partial case.

According to the fourth aspect of the invention, since the radial sizeof the front (on the internal combustion engine side) motor storagesection of the partial case for storing the first and second electricmotors is set larger than that of the rear side, the mountability to thebody of the FR-type vehicle is improved.

According to the fifth aspect of the invention, since the supportingmembers (partitions) extending from the casing member support the bothsides of the rotors of the first and second electric motors through anintermediary of the bearing members and hence the accuracy forsupporting the rotors improves, the gap between the stator and the rotormay be reduced and an output of the electric motors may be improved.Still more, since the supporting member (partition) between the firstand second electric motors is utilized in common, the length of thehybrid driving unit in the longitudinal direction may be shortened.Furthermore, since the partition is provided with the bearing membersfor supporting the rotors of the first and second electric motors,respectively, it becomes possible to steadily support the rotors of thefirst and second electric motors.

According to the sixth aspect of the invention, since the input shaft issupported by the inner peripheral face of the rotor of the firstelectric motor through the intermediary of the bearings provided on theouter peripheral face of the input shaft, the input shaft may besecurely supported by the rotor which is securely supported by thesupporting members even if the input shaft is passed through the innerperiphery of the two electric motors and the axial length thereofincreases. Accordingly, it enables the rigidity of the output shaft tobe assured and the diameter thereof to be suppressed, thus enabling thediameter of the hybrid driving unit to be reduced.

According to the seventh aspect of the invention, since the diameter ofthe first and second electric motors may be increased by disposing themon the front side while storing in one partial case by disposing thefirst electric motor, the second electric motor, the transmission andthe power splitting planetary gear in order from the side closer to theinternal combustion engine, the axial length of the unit may beshortened while assuring the output of the first and second electricmotors. Still more, since the transmission and the power splittingplanetary gear whose diameter may be reduced as compared to the electricmotors are disposed on the rear side, the diameter of the rear end partof the hybrid driving unit may be reduced and the mountability of thehybrid driving unit to the vehicle may be improved. Since the powersplitting planetary gear whose diameter may be reduced as compared tothe transmission is provided at the rearmost end, the diameter of therear end of the hybrid driving unit may be reduced further.

It is noted that the invention may be achieved without complicating thedisposition by coupling the first electric motor, the second electricmotor, the power splitting planetary gear and the transmission asdescribed in the eighth to twelfth aspects of the invention.

According to the thirteenth aspect of the invention, since the diameterof the first and second electric motors may be increased by disposingthem on the front side while storing in one partial case by disposingthe first electric motor, the second electric motor, the power splittingplanetary gear and the transmission in order from the side closer to theinternal combustion engine, the axial length of the unit may beshortened while assuring the output of the first and second electricmotors. Still more, since the power splitting planetary gear and thetransmission whose diameter may be reduced as compared to the electricmotors are disposed on the rear side, the diameter of the rear end partof the hybrid driving unit may be reduced and the mountability of thehybrid driving unit to the vehicle may be improved. Further, since theinput shaft coupled with the power splitting planetary gear may beshortened as compared to the case of providing the power splittingplanetary gear in the rearmost part by disposing the power splittingplanetary gear on the front side of the transmission, i.e., on the sideof the first and second electric motors, the input shaft may be readilymachined and whose accuracy may be improved.

It is noted that the invention may be achieved without complicating thedisposition by coupling the first electric motor, the power splittingplanetary gear, the second electric motor and the transmission asdescribed in the fourteenth to eighteenth aspects of the invention.

According to the nineteenth aspect of the invention, since thetransmission is composed of the planetary gear and may be provided onone axis, the diameter of the hybrid driving unit may be reduced.

According to the 20-th aspect of the invention, since the transmissionhas at least four shifting elements, the first shifting element iscoupled with the rotor of the second electric motor, the second shiftingelement is coupled with the output shaft, and the transmission hasbraking elements which are capable of fixing the third and fourthshifting elements to the case, respectively, it is possible to reducethe rotational speed of the rotor of the second electric motor at leastat two stages just by providing the brakes. If a clutch is used here toshift the speeds, a hydraulic servo of the clutch is provided on thecenter axis in general to supply oil to the hydraulic servo of theclutch and a plurality of seal rings are used to prevent leakage of oilbetween rotational members. In contrary to that, because the hydraulicservo of the inventive brake may be provided within the case, no sealring is required like the clutch and the hydraulic servo needs not beprovided on the center axis. Accordingly, because the axial length ofthe hybrid driving unit may be shortened by composing the two stages ofshift just by the brakes, the rigidity of the case is improved and theefficiency thereof may be improved through the reduction of the sealrings.

According to the 21-st aspect of the invention, the planetary gear ofthe transmission is composed of the Ravigneaux type planetary gear.Because the Ravigneaux type planetary gear allows the carriers of twoplanetary gears to be used in common, the axial length of thetransmission may be shortened. Still more, although the size of thecarrier increases by coupling the carrier with the output shaft and bycommonly using the carriers of the two planetary gears, it is possibleto suppress vibration caused by whirling of the transmission because thecarrier may be securely supported by coupling the carrier with theoutput shaft.

According to the 22-nd aspect of the invention, since the powersplitting planetary gear, the first electric motor, the second electricmotor and the transmission are disposed in order from the side closer tothe internal combustion engine, the first electric motor and the secondelectric motor may be stored in one partial case. Still more, becausethe two electric motors adjoin each other, a mechanism for cooling theelectric motors may be built in compact.

The invention may be achieved without complicating the disposition bycoupling the power splitting planetary gear, the first electric motor,the second electric motor and the transmission as described in the 23-rdaspect of the invention.

According to the 24-th aspect of the invention, since the secondelectric motor, the first electric motor, the power splitting planetarygear and the transmission are disposed in order from the side closer tothe internal combustion engine, the first electric motor and the secondelectric motor may be stored in one partial case. Still more, becausethe two electric motors adjoin each other, a mechanism for cooling theelectric motors may be built in compact.

The invention may be achieved without complicating the disposition bycoupling the transmission, the second electric motor, the first electricmotor and the transmission as described in the 25-th aspect of theinvention.

The 26-th aspect of the invention relates to the FR-type vehiclecarrying the inventive hybrid driving unit. The inventive vehicle allowsthe mountability of the hybrid driving unit to be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view diagrammatically showing an inventive vehiclecarrying an inventive hybrid driving unit;

FIG. 2 is a skeleton view showing the hybrid driving unit of a firstembodiment;

FIG. 3 is a longitudinal section view showing the structure of thehybrid driving unit of the first embodiment;

FIG. 4 is a skeleton view showing a first modification of the hybriddriving unit of the first embodiment;

FIG. 5 is a skeleton view showing a second modification of the hybriddriving unit of the first embodiment;

FIG. 6 is a skeleton view showing a third modification of the hybriddriving unit of the first embodiment;

FIG. 7 is a skeleton view showing a hybrid driving unit of a secondembodiment;

FIG. 8 is a longitudinal section view showing the structure of thehybrid driving unit of the second embodiment;

FIG. 9 is a skeleton view showing a first modification of the hybriddriving unit of the second embodiment;

FIG. 10 is a skeleton view showing a second modification of the hybriddriving unit of the second embodiment;

FIG. 11 is a skeleton view showing a third modification of the hybriddriving unit of the second embodiment;

FIG. 12 is a skeleton view showing a hybrid driving unit of a thirdembodiment; and

FIG. 13 is a skeleton view showing a hybrid driving unit of a fourthembodiment.

BEST MODES FOR CARRYING OUT THE INVENTION

Modes for carrying out the invention will be explained below withreference to the accompanying drawings. It is noted that the samereference numerals cited throughout several views denote the samecomponents or effects and an overlapped explanation thereof will beomitted.

First Embodiment

FIG. 1 shows an exemplary inventive vehicle, i.e., a vehicle 1 carryingan inventive hybrid driving unit. The vehicle 1 shown in the figure isan FR (front-engine and rear-drive) type vehicle and FIG. 1 is a planview diagrammatically showing the brief structure thereof. It is notedthat in an actual vehicle, the direction indicated by an arrow F in thefigure denotes the front side and the direction indicated by an arrow Rdenotes the rear side.

The vehicle 1 in the figure has a body 4 supported by right and leftfront wheels 2 and by right and left rear wheels 3, i.e., drivingwheels. An internal combustion engine 5 is mounted in the front part ofthe body 4 through an intermediary of a rubber mount not shown in amanner of adjusting a crankshaft 6, i.e., its output shaft, in thelongitudinal direction of the body. It is noted that in FIG. 1, theoutput shaft composed of a rear projection of the crankshaft is shown asthe crankshaft 6. A hybrid driving unit 7 is coupled with the rear endof the internal combustion engine 5.

The hybrid driving unit 7 has an input shaft 10 connected to thecrankshaft 6 of the internal combustion engine 5 via a damper unit 8, afirst electric motor 20, a power splitting planetary gear 21, atransmission 22, a second electric motor 23 (see FIG. 2) and an outputshaft 12 for outputting driving force. Here, the input shaft 10 and theoutput shaft 12 are disposed on one axis 13 such that the input shaft 10comes on the front side and the output shaft 12, on the rear side. Theseinput and output shafts 10 and 12 are disposed along the longitudinaldirection of the body 4 and are stored in a casing member 14 which islengthy in the longitudinal direction together with the first electricmotor 20, the power splitting planetary gear 21, the transmission 22 andthe second electric motor 23 described above. It is noted that thehybrid driving unit 7 will be described in detail later.

The output shaft 12 of the hybrid driving unit 7 projects from the rearend of the casing member 14 described above and extends further to therear to be coupled with a differential unit 17 via a flexible coupling15 and a publicly known propeller shaft 16 having a universal joint, acenter bearing and others not shown. The differential unit 17 is coupledwith the right and left rear wheels 3 described above via a left drivingshaft 18L and a right driving shaft 18R.

In the vehicle 1 constructed as described above, motive power generatedby the internal combustion engine 5 is inputted to the input shaft 10 ofthe hybrid driving unit 7 and is outputted from the output shaft 12after being regulated by the first electric motor 20, the powersplitting planetary gear 21, the transmission 22 and the second electricmotor 23 described later. Then, the motive power thus regulated istransmitted to the right and left rear wheels 3, i.e., the drivingwheels, via the propeller shaft 16 and others.

Next, a hybrid driving unit 7A of the present embodiment will beexplained as one example of the inventive hybrid driving unit 7 mountedto the vehicle 1 shown in FIG. 1. The outline of the whole hybriddriving unit 7A will be explained at first with reference to theskeleton view in FIG. 2 and then its concrete structure will be detailedwith reference to FIG. 3. It is noted that in these figures, thedirection indicated by an arrow F denotes the front side of the body(the internal combustion engine side) and the direction indicated by anarrow R denotes the rear side of the body (the differential unit side).

As shown in FIG. 2, the hybrid driving unit 7A comprises the firstelectric motor 20, the second electric motor 23, the transmission 22 andthe power splitting planetary gear 21 in order from the side closer tothe internal combustion engine 5 in FIG. 1, i.e., in order from thefront side to the rear side. All of these are stored within the casingmember 14 (see FIG. 1) and are disposed in line on (around) the axis 13.These devices will be explained below in the order of the first electricmotor 20, the second electric motor 23, the transmission 22 and thepower splitting planetary gear 21.

The first electric motor 20 has a stator 24 fixed to the casing member14 (see FIG. 1) and a rotor 25 rotatably supported on the innerdiametric side of the stator 24 (as for the position in the radialdirection of the casing member 14, the side closer to the center (theaxis 13) will be referred to as the ‘inner diametric side’ and the sidefurther from the center will be referred to as the ‘outer diametricside’ in the explanation hereinbelow). The rotor 25 of the firstelectric motor 20 is coupled with a sun gear S0 of the power splittingplanetary gear 21 described later. The first electric motor 20 mainlygenerates electricity based on the motive power inputted via the sungear S0 and drives the second electric motor 23 or charges an HV battery(hybrid driving battery) not shown via an inverter not shown.

The second electric motor 23 has a stator 28 fixed to the casing member14 (see FIG. 1) and a rotor 29 rotatably supported on the innerdiametric side of the stator 28. The rotor 29 of the second electricmotor 23 is coupled with a sun gear S1 of the transmission 22 describedlater. Similarly to the first electric motor 20 described above, thesecond electric motor 23 is connected to the HV battery via theinverter. However, their main functions differ from each other. That is,differing from the first electric motor 20 which is mainly used for thepurpose of power generation, the second electric motor 23 functionsmainly as a driving motor for assisting the motive power (driving force)of the vehicle 1. However, the second electric motor 23 also functionsas a generator when the brake is applied to the vehicle for example byregenerating vehicular inertia force as electrical energy.

The transmission 22 has a so-called Ravigneaux type planetary gear unit27 comprising one double pinion planetary gear and the single planetarygear that uses one of their pinions in common. The transmission 22 alsohas first and second brakes B1 and B2.

The planetary gear unit 27 is composed of two sun gears S1 and S2, acarrier CR1 supporting a pinion P1 and a pinion (common long pinion) P2,and a ring gear R1. Among the two pinions P1 and P2, the pinion P1engages with the sun gear S1 and the ring gear R1, and the pinion P2,i.e., the common long pinion, engages with the sun gear S2 and thepinion P1. The ring gear R1 of the planetary gear unit 27 is coupledwith the first brake B1 and the sun gear S2 is coupled with the secondbrake B2. As a whole, the sun gear S1, which is an input member (inputelement), is coupled with the rotor 29 of the second electric motor 23described above, and the carrier CR1, which is an output member (outputelement), is coupled with the output shaft 12 similarly to the ring gearR0 of the power splitting planetary gear 21 described later. Thistransmission 22 is arranged so as to be able to change two decelerationstages whose reduction ratios are different by engaging one of the firstand second brakes B1 and B2 while releasing the other and by releasingthe one while engaging the other. That is, the transmission 22 isarranged so as to change the degree of the motive power inputted fromthe second electric motor 23 described above via the sun gear S1 and totransmit it to the output shaft 12 via the carrier CR1 and the ring gearR0.

The power splitting planetary gear 21 is composed of the single pinionplanetary gear disposed coaxially with the input shaft 10. The powersplitting planetary gear 21 has a carrier (first rotary element) CR0supporting a plurality of pinions P0, a sun gear (second rotary element)S0 engaging with the pinion P0 and a ring gear (third rotary element) R0engaging with the pinion P0. The carrier CR0 of the power splittingplanetary gear 21 is coupled with the input shaft 10, the sun gear S0 iscoupled with the rotor 25 of the first electric motor 20 and the ringgear R0 is coupled with the output shaft 12. The power splittingplanetary gear 21 splits the motive power inputted to the carrier CR0via the input shaft 10 to the first electric motor 20 via the sun gearS0 and to the output shaft 12 via the ring gear R0 based on the controlon the revolution of the first electric motor 20. It is noted that thepower split to the first electric motor 20 is used for generatingelectricity and the power split to the output shaft 12 is used fordriving the vehicle 1.

In the hybrid driving unit 7A shown in FIG. 2, the four devices of thefirst electric motor 20, the second electric motor 23, the transmission22 and the power splitting planetary gear 21 are all disposed on theinput shaft 10. These are coupled each other as follows as shown in thefigure.

The input shaft 10 is coupled with the rear side of the carrier (firstrotary element) CR0 of the power splitting planetary gear 21 through theinner peripheral side of the first electric motor 20, the secondelectric motor 23, the transmission 22 and the power splitting planetarygear 21. The output shaft 12 is coupled with the ring gear (third rotaryelement) R0 of the power splitting planetary gear 21 from the rear sideand with the carrier (output element) CR1 of the transmission 22 throughthe outer peripheral side of the power splitting planetary gear 21. Therotor 25 of the first electric motor 20 is coupled with the sun gear(second rotary element) S0 of the power splitting planetary gear 21through between the outer peripheral side of the input shaft 10 and theinner peripheral side of the second electric motor 23 and thetransmission 22. Then, the rotor 29 of the second electric motor 23 iscoupled with the sun gear (input element) S1 through the innerperipheral side of the sun gear S2 of the transmission 22.

Regarding the longitudinal disposition of the first electric motor 20,the second electric motor 23, the transmission 22 and the powersplitting planetary gear 21 described above, i.e., the disposition alongthe axis 13, the first and second electric motors 20 and 23 are disposedadjacently to each other in the present invention. Still more, the firstelectric motor 20 is disposed on the side closer to the front (theinternal combustion engine) than the second electric motor 23 and at theforemost position in the present embodiment.

It is noted that the operation and effect of the hybrid driving unit 7Aexplained with reference to the skeleton view thereof in FIG. 2 will beexplained after detailing the concrete structure of the hybrid drivingunit 7A with reference to FIG. 3.

FIG. 3 shows an upper half portion of the longitudinal section view ofthe hybrid driving unit 7A including the axis 13.

The hybrid driving unit 7A shown in FIG. 3 comprises the input shaft 10and the output shaft 12 disposed on the axis 13 and the first electricmotor 20, the second electric motor 23, the transmission 22 and thepower splitting planetary gear 21 disposed around the axis 13. All ofthese devices are stored within the casing member 14, except of a partof the rear end of the output shaft 12 projecting out of the casingmember 14 to the rear.

Taking the readiness of assembly and others into account, the casingmember 14 is built in a body by connecting joints of a plurality ofpartial cases divided in the longitudinal direction along the axis 13.In the present embodiment shown in FIG. 3, the front partial case 14A isconnected in a body with the rear partial case 14B at the joint H toform the casing member 14. Note that the joints H is located in thevicinity between the second brake B2 and the first brake B1 of thetransmission 22. In the casing member 14, a plurality of partitions,i.e., partitions A, B, C and D, are formed at different positions in thelongitudinal direction in order from the front side. Among thesepartitions A through D, the partitions A and D are disposed near thefront and rear ends of the casing member 14, respectively, and the spacewithin the case between the partitions A and D is divided into threespaces by the partitions B and C longitudinally along the axis 13. Thesepartitions A through D act as reinforcing members of the casing member14 and are used for retaining bearings a through w described later andfor forming hydraulic chambers 40 and 45 described later. Among thepartitions A through D, the partitions A and B are formed by disc-likepartition members, i.e., separate members, fixed to the positions shownin the figure by fastening a plurality of bolts Ba and Bb (one each isshown in the figure) in the vicinity of the edge thereof. Still more,the radial size of the motor storage section 14A1 on the front side ofthe partition B in the partial case 14A is set to be larger than that ofthe motor storage section 14A2 on the rear side. It improves themountability of the hybrid driving unit 7A in mounting to the FR-typevehicle 1.

The first electric motor 20, the second electric motor 23, thetransmission 22 and the power splitting planetary gear 21 are storedwithin the three spaces divided by the partitions A through D,respectively. That is, the first electric motor 20 is stored in thespace between the partitions A and B, the second electric motor 23 isstored between the partitions B and C, and the transmission 22 and thepower splitting planetary gear 21 are stored between the partitions Cand D, respectively. Beginning from the first electric motor 20, thesedevices will be detailed in order below.

The first electric motor 20 comprises an AC permanent magnet synchronousmotor (brushless DC motor) for example. It is stored between thepartitions A and B and is disposed on the outer diametric side of theinput shaft 10 coaxially therewith. The first electric motor 20 has thestator 24 fixed to the inner peripheral face of the casing member 14 andthe rotor 25 rotatably disposed on the inner diametric side of thestator 24 apart from the stator 24 by a predetermined air gap G1. Theinner diametric side of the rotor 25 is formed into a cylindrical shapeand stages 30 and 31 are formed at the front and rear outer peripheralfaces of the cylindrical part. The casing member 14 rotatably supportsthe rotor 25 through an intermediary of bearings a and b fitted betweenthese stages 30 and 31 and the partitions A and B while being positionedin the longitudinal direction. A sleeve 70 extending to the rear isfitted around the outer peripheral face of the input shaft 10 at therear end of the cylindrical part. The edge of the sleeve 70 is coupledwith the rear end of the rotor 25 and the rear end thereof is coupledwith the sun gear S0 of the power splitting planetary gear 21 throughthe inside of the second electric motor 23 and the transmission 22described later. The cylindrical part of the rotor 25, the sleeve 70 andthe sun gear S0 are formed in a body and are relatively and rotatablysupported by the input shaft 10 through the intermediary of bearings c,d and e fixed to the outer peripheral face of the input shaft 10. It isnoted as for the longitudinal disposition that the bearings c and d aredisposed at the positions corresponding to the bearings a and b. Thecasing member 14 rotatably supports the input shaft 10 through theintermediary of the bearing c between the input shaft 10 and the rotor25 provided at the position axially overlapping with the bearing a andof the bearing a supporting the rotor 25 at the front end thereof andthrough the intermediary of the bearing w, provided between the inputshaft 10 and a hollow cylindrical section 12 f at the front end of theoutput shaft 12, and of the output shaft 12 rotatably supported by aboss portion 14 b of the casing member 14 through the intermediary ofbearings u and v. Because the rotor 25 of the first electric motor 20 isrotatably supported by the casing member 14 and the input shaft 10through the intermediary of the bearings a and b fixed to the partitionsA and B as described above, the position of the rotor 25 in thelongitudinal and radial directions may be assured accurately.Accordingly, even if a force bending the casing member 14 in thevertical or horizontal direction acts on the casing member 14, thepredetermined air gap G1 between the stator 24 and the rotor 25 may bekept accurately. It is noted that the first electric motor 20 isconnected to the HV battery via the inverter as described above. Themain function of the first electric motor 20 constructed as describedabove is to generate electricity and to charge the HV battery via theinverter based on the power split to the sun gear S0 of the powersplitting planetary gear 21 described later.

The second electric motor 23 comprises an AC permanent magnetsynchronous motor (brushless DC motor) for example and is disposed onthe outer diametric side of the input shaft 10 coaxially therewith. Thesecond electric motor 23 has the stator 28 fixed to the inner peripheralface of the casing member 14 and the rotor 29 rotatably disposed on theinner diametric side of the stator 28 apart from the stator 28 by apredetermined air gap G2. The inner diametric side of the rotor 29 isformed into a cylindrical shape and stages 48 and 50 are formed,respectively, at the front and rear outer peripheral faces of thecylindrical part. The casing member 14 rotatably supports the rotor 29through an intermediary of bearings f and g fitted between the stages 48and 50 and the partitions B and C while being positioned in thelongitudinal direction. The rear end of the cylindrical part is coupledwith the sun gear S1 of the transmission 22 described later via a sleeve63 fitted around the outer peripheral face of the sleeve 70 formed in abody with the rotor 25 described above. The cylindrical part of therotor 29, the sleeve 63 and the sun gear S1 mutually formed in a bodyare relatively rotatably supported by the sleeve 70 through anintermediary of bearings h, i and j fixed on the outer peripheral faceof the sleeve 70. It is noted that the bearings h and j are disposed atthe positions corresponding to the bearings f and g in terms of thedisposition in the longitudinal direction. Since the rotor 29 of thesecond electric motor 23 is rotatably supported by the casing member 14through the intermediary of the bearings f and g fixed to the partitionsB and C as described above, the longitudinal and radial positions of therotor 29 may be maintained accurately. Accordingly, even if a force thatmay bend the casing member 14 in the vertical or lateral direction actsthereon, the predetermined air gap G2 between the stator 28 and therotor 29 may be kept accurately. It is noted that the second electricmotor 23 is connected to the HV battery via the inverter similarly tothe first electric motor 20 described above.

The transmission 22 is disposed on the front side in the space betweenthe partitions C and D of the casing member 14. The transmission 22 hasthe Ravigneaux type planetary gear unit 27 disposed on the innerdiametric side and first and second brakes B1 and B2 disposed,respectively, on the rear and front sides on the outer diametric side.

The planetary gear unit 27 has a first sun gear S1 (hereinafter simplyreferred to as ‘the sun gear S1’), a second sun gear S2 (hereinaftersimply referred to as ‘the sun gear S2’) disposed on the front side ofthe sun gear S1 and slightly on the outer diametric side, the ring gearR1 disposed on the outer diametric side of the sun gear S1, the pinionP1 engaging with the sun gear S1 and the ring gear R1, the pinion P2composing the common long pinion and engaging with the sun gear S2 andthe pinion P1, and the carrier CR1 supporting these pinions P1 and P2.Beginning from the sun gear S1, these parts will be explained below.

The sun gear S1 is coupled with the rear end of the rotor 29 of thesecond electric motor 23 described above via the sleeve 63 describedabove. This sun gear S1 is relatively and rotatably supported togetherwith the sleeve 63 as described above by the sleeve 70 through anintermediary of the bearings i and j fitted to the outer peripheral faceof the input shaft 10.

The sun gear S2 is formed in a body with a flange portion 34 extendingfrom the front end of the sun gear S2 to the outer diametric side alongthe front carrier plate CR1 b of the carrier CR1 and with a drum portion35 extending to the rear from the outer diametric end of the flangeportion 34. The second brake B2 described later is interposed betweenthe outer peripheral face of this drum portion 35 and an innerperipheral spline 14 a of the inner peripheral face of the casing member14. The sun gear S2 is rotatably supported by bearings k and l fitted tothe outer peripheral face of the sleeve 63 formed in a body with the sungear S1 described above and bearings m and n fitted, respectively, tothe front and rear faces on the inner diametric side (basal end side) ofthe flange portion 34. It is noted that the bearing m is interposedbetween the flange portion 34 and the inner diametric rear face of thepartition C and the bearing n is interposed between the flange portion34 and the inner diametric front face of the front carrier plate CR1 bof the carrier CR1.

The ring gear R1 is provided with a flange portion 36 fixed at the rearend thereof and extending to the inner diametric side along the rearcarrier plate CR1 a of the carrier CR1 and is rotatably supported bybearings o and p fitted to the front and rear faces on the innerdiametric side of the flange portion 36. The bearing o is interposedbetween the flange portion 36 and the rear carrier plate CR1 a of thecarrier CR1 and the bearing p is interposed between the flange portion36 and a coupling member 64 described later. The first brake B1 isinterposed between the outer peripheral face of the ring gear R1 and theinner peripheral spline 14 a of the inner peripheral face of the casingmember 14.

The pinion P1 is rotatably supported by the carrier CR1 and is engagedwith the sun gear S1 described above on the inner diametric side andwith the ring gear R1 described above on the outer diametric side.

The pinion P2 is the common long pinion in which a large-diametric gearP2 a formed on the rear side and a small-diametric gear P2 b formed onthe front side are combined in a body. In the pinion P2, thelarge-diametric gear P2 a is engaged with the sun gear S2 describedabove and the small-diametric gear P2 b is engaged with the pinion P1described above.

The carrier CR1 rotatably supports the pinions P1 and P2 by the frontand rear carrier plates CR1 b and CR1 a. The rear carrier plate CR1 a iscoupled with the ring gear R0 of the power splitting planetary gear 21described later through the coupling member 64. The coupling member 64is connected to the inner diametric rear end of the rear carrier plateCR1 a of the carrier CR1. It extends at the front end thereof slightlyto the outer diametric side to retain a bearing p, bends and extends tothe rear and extends to the outer diametric side to be coupled with thefront end of the ring gear R0. The rear carrier plate CR1 a is rotatablysupported by the bearing q fitted between the inner diametric front faceand the rear face of the sun gear S1 and the bearing r fitted betweenthe carrier CR1 and the outer peripheral face of the sleeve 70 describedabove.

The first brake B1 has a number of discs and friction plates (brakeplates) and is spline-coupled between an outer peripheral spline formedon the outer peripheral face of the ring gear R1 described above and theinner peripheral spline 14 a formed on the inner peripheral face of thecasing member 14. A hydraulic actuator 37 for the first brake isdisposed on the rear side of the first brake B1. The hydraulic actuator37 has a piston 38 disposed on the rear side of the first brake B1 so asto be movable in the longitudinal direction, a first hydraulic chamber40 which is provided in a cylinder member 71 fixed to the innerperipheral face and the front face of a stepped portion 14 e of thecasing member 14 and into which the rear end of the piston 38 isoil-tightly fitted, and a return spring (compression spring) 42interposed between a retainer 41 fixed to the cylinder member 71 and theinner diametric front face of the piston 38 to bias the piston 38 to therear.

The second brake B2 is disposed just before the first brake B1 describedabove. The second brake B2 has a number of discs and friction plates(brake plates) and is spline-coupled between an outer peripheral splineformed on the outer peripheral face of the drum portion 35 combined withthe sun gear S2 described above and the inner spline 14 a formed on theinner peripheral face of the casing member 14. A hydraulic actuator 43for the second brake is disposed on the front side of the second brakeB2. The hydraulic actuator 43 has a piston 44 disposed before the secondbrake B2 so as to be movable in the longitudinal direction, a secondhydraulic chamber 45 which is provided at the outer diametric rear faceof the partition C and into which the front end of the piston 44 isoil-tightly fitted, and a return spring (compression spring) 47interposed between a retainer 46 fixed to the casing member 14 and theinner diametric rear face of the piston 44 to bias the piston 44 to thefront.

In the transmission 22 constructed as described above, an output fromthe second electric motor 23 is transmitted to the sun gear S1 via thesleeve 63. In a low state, the first brake B1 is engaged and the secondbrake B2 is released. Accordingly, the ring gear R1 is locked and thesun gear S2 is freely rotatable in this state. The revolution of thefirst sun gear S1 described above is largely reduced via the pinion P1and is transmitted to the carrier CR1. The revolution of the carrier CR1is then transmitted to the output shaft 12.

When the transmission 22 is in a high state, the first brake B1 isreleased and the second brake B2 is engaged. Accordingly, the sun gearS2 is locked and the ring gear R1 is freely rotatable in this state. Inthis state, the revolution of the sun gear S1 is transmitted to thepinion P1 and the pinion P2 engages with the locked sun gear S2. Then,the carrier CR1 moves around the sun gear at a restricted predeterminednumber of revolution and the revolution of the carrier CR1 reducedrelatively in small is transmitted to the output shaft 12 at this time.

Thus, the transmission 22 transmits the largely reduced revolution tothe output shaft 12 in the low state by engaging the first brake B1 andby releasing the second brake B2, respectively. In contrary, ittransmits the revolution reduced relatively in small to the output shaft12 by releasing the first brake B1 and by engaging the second brake B2,respectively. Because the transmission 22 is thus capable of shifting inthe two stages, the second electric motor 23 may be downsized. That is,the transmission 22 enables to use a small electric motor, to transmitsufficient driving torque to the output shaft 12 in the low state instarting the vehicle 1 when high torque is required, and to prevent therotor 29 from rotating at high-speed by putting it in the high statewhen the output shaft 12 is rotating at high-speed.

The power splitting planetary gear 21 is disposed in the rear half ofthe space between the partitions C and D of the casing member 14, i.e.,on the rear side of the transmission 22 described above. The powersplitting planetary gear 21 is composed of the single pinion planetarygear disposed coaxially with the input shaft 10 as described above andhas the ring gear (third rotary element) R0, the sun gear (second rotaryelement) S0 and the carrier (first rotary element) CR0 supporting thepinions P0. Among them, the front end of the ring gear R0 is coupledwith the coupling member 64 described above and the rear end thereofextends to the rear and is fixed to the outer diametric end of a flangeportion 61 extending to the outer diametric side from the outerperipheral face near the front end of the output shaft 12 along the rearcarrier plate CR0 a. The rear carrier plate CR0 a of the carrier CR0 iscoupled with the rear end of the input shaft 10. The sun gear S0 iscoupled with the rear end of the rotor 25 of the first electric motor 20via the sleeve 70 described above. In the power splitting planetary gear21, the sun gear S0 is rotatably supported by a bearing e fitted betweenthe input shaft 10 and the outer peripheral face of the rear end of theinput shaft 10 and the carrier CR0 is rotatably supported by a bearing sfitted between the inner diametric front face of the rear carrier plateCR0 a and the rear end face of the sun gear S0 and a bearing t fittedbetween the inner diametric rear face and the rear end face of theoutput shaft 12. Thus, in the power splitting planetary gear 21, thecarrier CR0, which is the input section, is fixed to the input shaft 10and the sun gear S0 and the ring gear R0, which are the output sections(to which power is split), are coupled with the rear end of the rotor 25of the first electric motor 20 and with the front end of the outputshaft 12, respectively. That is, the power splitting planetary gear 21is arranged so as to split the power of the internal combustion engine 5inputted to the carrier CR0 via the input shaft 10 (see FIG. 1) to theside of the first electric motor 20 via the sun gear S0 and to the sideof the output shaft 12 via the ring gear R0. The ratio of split of powerat this time is decided based on the state of revolution of the firstelectric motor 20. That is, when the rotor 25 of the first electricmotor 20 is caused to generate a large power, an amount of powergenerated by the first electric motor 20 increases and the poweroutputted to the output shaft 12 is reduced to that extent. When therotor 25 of the first electric motor 20 is caused to generate a smallpower in contrary, an amount of power generated by the first electricmotor 20 decreases and the power outputted to the output shaft 12increases to that extent.

The casing member 14 storing the first electric motor 20, the secondelectric motor 23, the transmission 22 and the power splitting planetarygear 21 as described above has a cylindrical section 14 b which extendsto the rear on the inner diametric side of the partition D at the rearend thereof. The casing member 14 rotatably supports the output shaft 12by the cylindrical section 14 b through an intermediary of bearings uand v. The front end of the output shaft 12 is formed as a hollowcylindrical portion 12 f into which a boss portion 10 a projecting fromthe rear end of the input shaft 10 is inserted. Then, a bearing w, whichcorresponds to the bearing u, is fitted between the inner peripheralface of the hollow cylindrical portion 12 f and the outer peripheralface of the boss portion 10 a. The input shaft 10 is rotatably supportedby the output shaft 12 at the rear end thereof through the intermediaryof the bearing w.

A coupling section 14 d at the front end of the casing member 14 isconnected with the internal combustion engine 5 rubber-mounted to thebody 4 (see FIG. 1) and the rear end thereof is rubber-mounted to a partof the body by utilizing a mounting section not shown.

In the hybrid driving unit 7A constructed as described above, the motivepower inputted to the input shaft 10 is inputted to the carrier CR0 ofthe power splitting planetary gear 21 to be split (divided) to the sungear S0 and the ring gear R0 as shown in the skeleton view of FIG. 2.Among them, the motive power split to the sun gear S0 is inputted to therotor 25 of the first electric motor 20 to be used to generateelectricity. The electricity thus generated is charged to the HV batteryvia the inverter. The second electric motor 23 receives the electricitysupplied from the HV battery via the inverter and drives the outputshaft 12 via the transmission 22 and the ring gear R0. That is, themotive power from the internal combustion engine 5 is combined with thepower from the second electric motor 23 and is outputted to the outputshaft 12. It is noted that because the transmission 22 is arranged so asto be capable of switching between the high and low states as describedabove, power corresponding to the high or low state is outputted to theoutput shaft 12.

Since the first electric motor 20 and the second electric motor 23 aredisposed adjacently to each other on the axis 13 as shown in FIG. 3 inthe present embodiment, the parts of the case storing these first andsecond electric motors 20 and 23 may be combined, thus facilitating theaccommodation in producing the unit in series. It also brings about sucheffects that a number of parts and, hence the cost, may be reduced, theaccuracy for supporting the two electric motors 20 and 23 may beimproved, the length of power cables of the two electric motors 20 and23 maybe almost equalized regardless of the position of a controller forcontrolling them, the length of the cable may be minimized when theinverter is disposed within an engine room on the front side of thevehicle, thus minimizing the loss of electricity, and others.

Next, a first modification (corresponding to the tenth aspect of theinvention) of the hybrid driving unit 7A of the present embodiment willbe explained with reference to a skeleton view in FIG. 4.

As shown in FIG. 4, the hybrid driving unit 7A comprises the firstelectric motor 20, the second electric motor 23, the transmission 22 andthe power splitting planetary gear 21 in order from the side closer tothe internal combustion engine 5 in FIG. 1, i.e., in order from thefront to the rear. All of these are stored within the casing member 14(see FIG. 1) and are disposed in line around the axis 13 in order fromthe front. These devices will be explained below in the order of thefirst electric motor 20, the second electric motor 23, the transmission22 and the power splitting planetary gear 21.

The first electric motor 20 has the stator 24 fixed to the casing member14 (see FIG. 1) and the rotor 25 rotatably supported on the innerdiametric side of the stator 24. The rotor 25 of the first electricmotor 20 is coupled with a ring gear R0 of the power splitting planetarygear 21 described later. The first electric motor 20 generateselectricity based on the motive power inputted via the ring gear R0 anddrives the second electric motor 23 or charges the HV battery (hybriddriving battery) not shown via the inverter not shown.

The second electric motor 23 has the stator 28 fixed to the casingmember 14 (see FIG. 1) and the rotor 29 rotatably supported on the innerdiametric side of the stator 28. The rotor 29 of the second electricmotor 23 is coupled with the sun gear S1 of the transmission 22described later. Similarly to the first electric motor 20 describedabove, the second electric motor 23 is connected to the HV battery viathe inverter. The second electric motor 23 functions mainly as a drivingmotor for assisting the motive power of the vehicle 1. However, thesecond electric motor 23 also functions as a generator when the brake isapplied to the vehicle for example by regenerating vehicular inertiaforce as electrical energy.

The transmission 22 has the so-called Ravigneaux type planetary gearunit 27 comprising one double pinion planetary gear and the singleplanetary gear that uses one of their pinions in common. Thetransmission 22 also has the first and second brakes B1 and B2.

The planetary gear unit 27 is composed of two sun gears S1 and S2, thecarrier CR1 supporting the pinion P1 and the pinion (common long pinion)P2, and the ring gear R1. Among the two pinions P1 and P2, the pinion P1engages with the sun gear S1 and the ring gear R1, and the pinion P2,i.e., the common long pinion, engages with the sun gear S2 and thepinion P1. The ring gear R1 of the planetary gear unit 27 is coupledwith the first brake B1 and the sun gear S2 is coupled with the secondbrake B2. As a whole, the sun gear S1, which is an input member (inputelement), is coupled with the rotor 29 of the second electric motor 23described above, and the carrier CR1, which is an output member (outputelement), is coupled with the output shaft 12. This transmission 22 isarranged so as to be able to change two deceleration stages whosereduction ratios are different by engaging one of the first and secondbrakes B1 and B2 while releasing the other and by releasing the onewhile engaging the other. That is, the transmission 22 is arranged so asto change the degree of the motive power inputted from the secondelectric motor 23 described above via the sun gear S1 and to transmit itto the output shaft 12 via the carrier CR1.

The power splitting planetary gear 21 is composed of the single pinionplanetary gear disposed coaxially with the output shaft 12. The powersplitting planetary gear 21 has the carrier (first rotary element) CR0supporting a plurality of pinions P0, the sun gear (third rotaryelement) S0 engaging with the pinion P0 and the ring gear (second rotaryelement) R0 engaging with the pinion P0. The carrier CR0 of the powersplitting planetary gear 21 is coupled with the input shaft 10, the ringgear R0 is coupled with the rotor 25 of the first electric motor 20 andthe sun gear S0 is coupled with the output shaft 12. The power splittingplanetary gear 21 constructed as described above splits the motive powerinputted to the carrier CR0 via the input shaft 10 to the first electricmotor 20 via the ring gear R0 and to the output shaft 12 via the sungear S0 based on the control on the revolution of the first electricmotor 20. It is noted that the power split to the first electric motor20 is used for generating electricity and the power split to the outputshaft 12 is used for driving the vehicle 1.

In the hybrid driving unit 7A shown in FIG. 4, among the four devices ofthe first electric motor 20, the second electric motor 23, thetransmission 22 and the power splitting planetary gear 21, the formerthree devices are disposed on the input shaft 10 and the remaining powersplitting planetary gear 21 is disposed on the output shaft 12. Theseare coupled each other as follows as shown in the figure.

The input shaft 10 is coupled with the front side (the transmission 22side) of the carrier (first rotary element) CR0 of the power splittingplanetary gear 21 through the inner peripheral side of the firstelectric motor 20, the second electric motor 23 and the transmission 22.The output shaft 12 is coupled with the sun gear (third rotary element)S0 of the power splitting planetary gear 21 from the rear side and withthe carrier (output element) CR1 of the transmission 22 through theouter peripheral side of the power splitting planetary gear 21. Therotor 25 of the first electric motor 20 is coupled with the ring gear(second rotary element) R0 of the power splitting planetary gear 21through between the outer peripheral side of the input shaft 10 and theinner peripheral side of the second electric motor 23 and thetransmission 22. Then, the rotor 29 of the second electric motor 23 iscoupled with the sun gear (input element) S1 through the innerperipheral side of the sun gear S2 of the transmission 22.

Next, a second modification (corresponding to the eleventh aspect of theinvention) of the hybrid driving unit 7A of the present embodiment willbe explained with reference to a skeleton view in FIG. 5.

As shown in FIG. 5, the hybrid driving unit 7A comprises the firstelectric motor 20, the second electric motor 23, the transmission 22 andthe power splitting planetary gear 21 in order from the side closer tothe internal combustion engine 5 in FIG. 1, i.e., in order from thefront to the rear. All of these are stored within the casing member 14(see FIG. 1) and are disposed in line around the axis 13 in order fromthe front along the axis 13. These devices will be explained below inthe order of the first electric motor 20, the second electric motor 23,the transmission 22 and the power splitting planetary gear 21.

The first electric motor 20 has the stator 24 fixed to the casing member14 (see FIG. 1) and the rotor 25 rotatably supported on the innerdiametric side of the stator 24. The rotor 25 of the first electricmotor 20 is coupled with a sun gear S0 of the power splitting planetarygear 21 described later. The first electric motor 20 arranged asdescribed above mainly generates electricity based on the motive powerinputted via the sun gear S0 and drives the second electric motor 23 orcharges the HV battery (hybrid driving battery) not shown via theinverter not shown.

The second electric motor 23 has the stator 28 fixed to the casingmember 14 (see FIG. 1) and the rotor 29 rotatably supported on the innerdiametric side of the stator 28. The rotor 29 of the second electricmotor 23 is coupled with the sun gear S1 of the transmission 22described later. Similarly to the first electric motor 20 describedabove, the second electric motor 23 is connected to the HV battery viathe inverter. The second electric motor 23 functions mainly as a drivingmotor for assisting the motive power (driving force) of the vehicle 1.However, the second electric motor 23 also functions as a generator whenthe brake is applied to the vehicle for example by regeneratingvehicular inertia force as electrical energy.

The transmission 22 has the so-called Ravigneaux type planetary gearunit 27 comprising one double pinion planetary gear and the singleplanetary gear that uses one of their pinions in common. Thetransmission 22 also has the first and second brakes B1 and B2.

The planetary gear unit 27 is composed of the two sun gears S1 and S2,the carrier CR1 supporting the pinion P1 and the pinion (common longpinion) P2, and the ring gear R1. Among the two pinions P1 and P2, thepinion P1 engages with the sun gear S1 and the ring gear R1, and thepinion P2, i.e., the common long pinion, engages with the sun gear S2and the pinion P1. The ring gear R1 of the planetary gear unit 27 iscoupled with the first brake B1 and the sun gear S2 is coupled with thesecond brake B2. As a whole, the sun gear S1, which is an input member(input element), is coupled with the rotor 29 of the second electricmotor 23 described above, and the carrier CR1, which is an output member(output element), is coupled with the output shaft 12. This transmission22 is arranged so as to be able to change two deceleration stages whosereduction ratios are different by engaging one of the first and secondbrakes B1 and B2 while releasing the other and by releasing the onewhile engaging the other as described later. That is, the transmission22 is arranged so as to change the degree of the motive power inputtedfrom the second electric motor 23 described above via the sun gear S1and to transmit it to the output shaft 12 via the carrier CR1.

The power splitting planetary gear 21 is composed of the double pinionplanetary gear disposed coaxially with the input shaft 10. The powersplitting planetary gear 21 has the carrier (third rotary element) CR0supporting the plurality of pinions P0 (P01 and P02), the sun gear(second rotary element) S0 engaging with the pinion P01 and the ringgear (first rotary element) R0 engaging with the pinion P02. The ringgear R0 of the power splitting planetary gear 21 is coupled with theinput shaft 10, the sun gear S0 is coupled with the rotor 25 of thefirst electric motor 20 and the carrier CR0 is coupled with the outputshaft 12. The power splitting planetary gear 21 splits the motive powerinputted to the ring gear R0 via the input shaft 10 to the firstelectric motor 20 via the sun gear S0 and to the output shaft 12 via thecarrier CR0 based on the control on the revolution of the first electricmotor 20. It is noted that the power split to the first electric motor20 is used for generating electricity and the power split to the outputshaft 12 is used for driving the vehicle 1.

In the hybrid driving unit 7A shown in FIG. 5, all of the four devicesof the first electric motor 20, the second electric motor 23, thetransmission 22 and the power splitting planetary gear 21 are disposedon the input shaft 10. These are coupled each other as follows as shownin the figure.

The input shaft 10 is coupled with the ring gear (first rotary element)R0 of the power splitting planetary gear 21 through the inner peripheralside of the first electric motor 20, the second electric motor 23, thetransmission 22 and the power splitting planetary gear 21 and behind thepower splitting planetary gear 21. The output shaft 12 is coupled withthe front side (the transmission 22 side) of the carrier (third rotaryelement) CR0 of the power splitting planetary gear 21 through the outerperipheral side of the power splitting planetary gear 21 and with thecarrier (output element) CR1 of the transmission 22. The rotor 25 of thefirst electric motor 20 is coupled with the sun gear (second rotaryelement) S0 of the power splitting planetary gear 21 through between theouter peripheral side of the input shaft 10 and the inner peripheralside of the second electric motor 23 and the transmission 22. Then, therotor 29 of the second electric motor 23 is coupled with the sun gear(input element) S1 through the inner peripheral side of the sun gear S2of the transmission 22.

Next, a third modification (corresponding to the twelfth aspect of theinvention) of the hybrid driving unit 7A of the present embodiment willbe explained with reference to a skeleton view in FIG. 6.

As shown in FIG. 6, the hybrid driving unit 7A comprises the firstelectric motor 20, the second electric motor 23, the transmission 22 andthe power splitting planetary gear 21 in order from the side closer tothe internal combustion engine 5 in FIG. 1, i.e., in order from thefront to the rear. All of these are stored within the casing member 14(see FIG. 1) and are disposed in line around the axis 13 in order fromthe front along the axis 13. These devices will be explained below inthe order of the first electric motor 20, the second electric motor 23,the transmission 22 and the power splitting planetary gear 21.

The first electric motor 20 has the stator 24 fixed to the casing member14 (see FIG. 1) and the rotor 25 rotatably supported on the innerdiametric side of the stator 24. The rotor 25 of the first electricmotor 20 is coupled with the carrier CR0 of the power splittingplanetary gear 21 described later. The first electric motor 20 mainlygenerates electricity based on the motive power inputted via the carrierCR0 and drives the second electric motor 23 or charges the HV battery(hybrid driving battery) not shown via the inverter not shown.

The second electric motor 23 has the stator 28 fixed to the casingmember 14 (see FIG. 1) and the rotor 29 rotatably supported on the innerdiametric side of the stator 28. The rotor 29 of the second electricmotor 23 is coupled with the sun gear S1 of the transmission 22described later. Similarly to the first electric motor 20 describedabove, the second electric motor 23 is connected to the HV battery viathe inverter. The second electric motor 23 mainly functions as a drivingmotor for assisting the motive power (driving force) of the vehicle 1.However, the second electric motor 23 also functions as a generator whenthe brake is applied to the vehicle for example by regeneratingvehicular inertia force as electrical energy.

The transmission 22 has the so-called Ravigneaux type planetary gearunit 27 comprising one double pinion planetary gear and the singleplanetary gear that uses one of their pinions in common. Thetransmission 22 also has the first and second brakes B1 and B2.

The planetary gear unit 27 is composed of two sun gears S1 and S2, thecarrier CR1 supporting the pinion P1 and the pinion (common long pinion)P2, and the ring gear R1. Among the two pinions P1 and P2, the pinion P1engages with the sun gear S1 and the ring gear R1, and the pinion P2,i.e., the common long pinion, engages with the sun gear S2 and thepinion P1. The ring gear R1 of the planetary gear unit 27 is coupledwith the first brake B1 and the sun gear S2 is coupled with the secondbrake B2. As a whole, the sun gear S1, which is an input member (inputelement), is coupled with the rotor 29 of the second electric motor 23described above, and the carrier CR1, which is an output member (outputelement), is coupled with the output shaft 12. This transmission 22 isarranged so as to be able to change two deceleration stages whosereduction ratios are different by engaging one of the first and secondbrakes B1 and B2 while releasing the other and by releasing the onewhile engaging the other as described later. That is, the transmission22 is arranged so as to change the degree of the motive power inputtedfrom the second electric motor 23 described above via the carrier CR1and to transmit it to the output shaft 12 via the carrier CR1.

The power splitting planetary gear 21 is composed of the double pinionplanetary gear disposed coaxially with the input shaft 10. The powersplitting planetary gear 21 has the carrier (second rotary element) CR0supporting the plurality of pinions P0 (P01 and P02), the sun gear(third rotary element) S0 engaging with the pinion P1 and the ring gear(first rotary element) R0 engaging with the pinion P02. The ring gear R0of the power splitting planetary gear 21 is coupled with the input shaft10, the carrier CR0 is coupled with the rotor 25 of the first electricmotor 20 and the sun gear S0 is coupled with the output shaft 12. Thepower splitting planetary gear 21 described above splits the motivepower inputted to the ring gear R0 via the input shaft 10 to the firstelectric motor 20 via the carrier CR0 and to the output shaft 12 via thesun gear S0 based on the control on the revolution of the first electricmotor 20. It is noted that the power split to the first electric motor20 is used for generating electricity and the power split to the outputshaft 12 is used for driving the vehicle 1.

In the hybrid driving unit 7A shown in FIG. 6, all of the four devicesof the first electric motor 20, the second electric motor 23, thetransmission 22 and the power splitting planetary gear 21 are disposedon the input shaft 10. These are coupled each other as follows as shownin the figure.

The input shaft 10 is coupled with the ring gear (first rotary element)R0 of the power splitting planetary gear 21 through the inner peripheralside of the first electric motor 20, the second electric motor 23, thetransmission 22 and the power splitting planetary gear 21 and behind thepower splitting planetary gear 21. The output shaft 12 is coupled withthe sung gear (third rotary element) S0 of the power splitting planetarygear 21 through the outer peripheral side of the power splittingplanetary gear 21 and between the power splitting planetary gear 21 andthe transmission 22 and with the carrier (output element) CR1 of thetransmission 22. The rotor 25 of the first electric motor 20 is coupledwith the rear side of the carrier (second rotary element) CR0 of thepower splitting planetary gear 21 through between the outer peripheralside of the input shaft 10 and the inner peripheral side of the secondelectric motor 23, the transmission 22 and the power splitting planetarygear 21. Then, the rotor 29 of the second electric motor 23 is coupledwith the sun gear (input element) S1 through the inner peripheral sideof the sun gear S2 of the transmission 22.

Second Embodiment

Next, a hybrid driving unit 7B of a second embodiment will be explainedas another example of the inventive hybrid driving unit 7 mounted to thevehicle 1 shown in FIG. 1. The outline of the whole hybrid driving unit7B will be explained at first with reference to the skeleton view inFIG. 7 and then its concrete structure will be detailed with referenceto FIG. 8. It is noted that in these figures, the direction indicated byan arrow F denotes the front side of the body (the internal combustionengine side) and the direction indicated by an arrow R denotes the rearside thereof (the differential unit side).

As shown in FIG. 7, the hybrid driving unit 7B comprises the firstelectric motor 20, the second electric motor 23, the power splittingplanetary gear 21 and the transmission 22 in order from the side closerto the internal combustion engine 5 in FIG. 1, i.e., in order from thefront to the rear. All of these are stored within the casing member 14(see FIG. 1) and are disposed in line around the axis 13 in order alongthe axis 13. These devices will be explained below in the order of thefirst electric motor 20, the second electric motor 23, the powersplitting planetary gear 21 and the transmission 22.

The first electric motor 20 has the stator 24 fixed to the casing member14 (see FIG. 1) and the rotor 25 rotatably supported on the innerdiametric side of the stator 24. The rotor 25 of the first electricmotor 20 is coupled with the sun gear S0 of the power splittingplanetary gear 21 described later. The first electric motor 20constructed as described above mainly generates electricity based on themotive power inputted via the sun gear S0 and drives the second electricmotor 23 or charges the HV battery (hybrid driving battery) not shownvia the inverter not shown.

The second electric motor 23 has the stator 28 fixed to the casingmember 14 (see FIG. 1) and the rotor 29 rotatably supported on the innerdiametric side of the stator 28. The rotor 29 of the second electricmotor 23 is coupled with a sun gear S1 of the transmission 22 describedlater. Similarly to the first electric motor 20 described above, thesecond electric motor 23 is connected to the HV battery via theinverter. However, their main functions differ from each other. That is,differing from the first electric motor 20 which is mainly used forgenerating electricity, the second electric motor 23 functions mainly asa driving motor for assisting the motive power (driving force) of thevehicle 1. However, the second electric motor 23 also functions as agenerator when the brake is applied to the vehicle for example byregenerating vehicular inertia force as electrical energy.

The power splitting planetary gear 21 is composed of the single pinionplanetary gear disposed coaxially with the input shaft 10. The powersplitting planetary gear 21 has the carrier (first rotary element) CR0supporting a plurality of pinions P0, the sun gear (second rotaryelement) S0 engaging with the pinion P0 and the ring gear (third rotaryelement) R0 engaging with the pinion P0. The carrier CR0 of the powersplitting planetary gear 21 is coupled with the input shaft 10, the sungear S0 is coupled with the rotor 25 of the first electric motor 20 andthe ring gear R0 is coupled with the output shaft 12. The powersplitting planetary gear 21 constructed as described above splits themotive power inputted to the carrier CR0 via the input shaft 10 to thefirst electric motor 20 via the sun gear S0 and to the output shaft 12via the ring gear R0 based on the control on the revolution of the firstelectric motor 20. It is noted that the power split to the firstelectric motor 20 is used for generating electricity and the power splitto the output shaft 12 is used for driving the vehicle 1.

The transmission 22 has the so-called Ravigneaux type planetary gearunit 27 comprising one double pinion planetary gear and the singleplanetary gear that uses one of their pinions in common. Thetransmission 22 also has the first and second brakes B1 and B2.

The planetary gear unit 27 is composed of two sun gears S1 and S2, thecarrier CR1 supporting the pinion P1 and the pinion (common long pinion)P2, and the ring gear R1. Among the two pinions P1 and P2, the pinion P1engages with the sun gear S1 and the ring gear R1, and the pinion P2,i.e., the common long pinion, engages with the sun gear S2 and thepinion P1. The ring gear R1 of the planetary gear unit 27 is coupledwith the first brake B1 and the sun gear S2 is coupled with the secondbrake B2. As a whole, the sun gear S1, which is an input member (inputelement), is coupled with the rotor 29 of the second electric motor 23described above, and the carrier CR1, which is an output member (outputelement), is coupled with the output shaft 12. This transmission 22 isarranged so as to be able to change two deceleration stages whosereduction ratios are different by engaging one of the first and secondbrakes B1 and B2 while releasing the other and by releasing the onewhile engaging the other. That is, the transmission 22 is arranged so asto change the degree of the motive power inputted from the secondelectric motor 23 described above via the sun gear S1 and to transmit itto the output shaft 12 via the carrier CR1.

In the hybrid driving unit 7B shown in FIG. 7, among the four devices ofthe first electric motor 20, the second electric motor 23, the powersplitting planetary gear 21 and the transmission 22, the former threedevices are disposed on the input shaft 10 and the remainingtransmission 22 is disposed on the output shaft 12. These are coupledeach other as follows as shown in the figure.

The input shaft 10 is coupled with the rear side of the carrier (firstrotary element) CR0 of the power splitting planetary gear 21 through theinner peripheral side of the first electric motor 20, the secondelectric motor 23 and the power splitting planetary gear 21. The outputshaft 12 is coupled with the carrier (output element) CR1 of thetransmission 22 and with the ring gear (third rotary element) R0 of thepower splitting planetary gear 21 through the inner peripheral side ofthe transmission 22 and between the transmission 22 and the powersplitting planetary gear 21. The rotor 25 of the first electric motor 20is coupled with the sun gear (second rotary element) S0 of the powersplitting planetary gear 21 through between the outer peripheral side ofthe input shaft 10 and the inner peripheral side of the second electricmotor 23. Then, the rotor 29 of the second electric motor 23 is coupledwith the sun gear (input element) S1 by passing between the secondelectric motor 23 and the power splitting planetary gear 21, through theouter peripheral side of the power splitting planetary gear 21, betweenthe power splitting planetary gear 21 and the transmission 22 andthrough the inner peripheral side of the sun gear S2 of the transmission22.

Here, with regard the longitudinal disposition of the first electricmotor 20, the second electric motor 23, the power splitting planetarygear 21 and the transmission 22 described above, i.e., the dispositionalong the axis 13, the first and second electric motors 20 and 23 aredisposed adjacently to each other in the invention. Still more, thefirst electric motor 20 is disposed on the side closer to the front (theside of the internal combustion engine) than the second electric motor23 and at the foremost position.

It is noted that the operation and effect of the hybrid driving unit 7Bexplained with reference to the skeleton view in FIG. 7 will beexplained after detailing the concrete structure of the hybrid drivingunit 7B with reference to FIG. 8.

FIG. 8 shows an upper half portion of the longitudinal section view ofthe hybrid driving unit 7B including the axis 13.

The hybrid driving unit 7B shown in FIG. 8 comprises the input shaft 10and the output shaft 12 disposed on the axis 13 and the first electricmotor 20, the second electric motor 23, the power splitting planetarygear 21 and the transmission 22 disposed around the axis 13. All ofthese devices are stored within the casing member 14, except of a partof the rear end of the output shaft 12 projecting out of the casingmember 14 to the rear.

Taking the readiness of assembly and others into account, the casingmember 14 is divided into a plurality of parts in the longitudinaldirection along the axis 13 and is formed in a body by combining jointsof the respective parts. In the embodiment shown in FIG. 8, the casingmember 14 is built by combining the front partial case 14A with the rearpartial case 14B at the joint H. Note that the joint H is provided atthe part storing the power splitting planetary gear 21 and thetransmission 22, or more specifically in the vicinity between the secondand first brakes B2 and B1 of the transmission 22. In the casing member14, a plurality of partitions, i.e., partitions A, B, C and D, areformed at different positions in the longitudinal direction in orderfrom the front side. Among the partitions A through D, the partitions Aand D are disposed in the vicinity of the front and rear ends of thecasing member 14, respectively, and the space within the case betweenthe partitions A and D is divided into three spaces by the partitions Band C longitudinally along the axis 13. These partitions A through D actas members for reinforcing the casing member 14 and are used forretaining bearings a through z described later and for forming thehydraulic chambers 40 and 45 described later. Among the partitions Athrough D, the partitions A and B are formed by disc-like partitionmembers, i.e., separate members, fixed to the positions shown in thefigure by fastening a plurality of bolts Ba and Bb (one each is shown inthe figure) in the vicinity of the edge thereof. Still more, the radialsize of the motor storage section 14A1 on the front side of thepartition B in the partial case 14A is set to be larger than that of themotor storage section 14A2 on the rear side. It improves themountability of the hybrid driving unit 7A in mounting to the FR-typevehicle 1.

The first electric motor 20, the second electric motor 23, the powersplitting planetary gear 21 and the transmission 22 are stored withinthe three spaces divided by the partitions A through D, respectively.That is, the first electric motor 20 is stored in the space between thepartitions A and B, the second electric motor 23 is stored between thepartitions B and C, and the transmission 22 and the power splittingplanetary gear 21 are stored between the partitions C and D,respectively. Beginning from the first electric motor 20, these deviceswill be detailed in order below.

The first electric motor 20 comprises an AC permanent magnet synchronousmotor (brushless DC motor) for example. It is stored between thepartitions A and B and is disposed on the outer diametric side of theinput shaft 10 coaxially therewith. The first electric motor 20 has thestator 24 fixed to the inner peripheral face of the casing member 14 andthe rotor 25 rotatably disposed on the inner diametric side of thestator 24 apart from the stator 24 by a predetermined air gap G1. Theinner diametric side of the rotor 25 is formed into a cylindrical shapeand stages 30 and 31 are formed at the front and rear outer peripheralfaces of the cylindrical part. The casing member 14 rotatably supportsthe rotor 25 through an intermediary of bearings a and b fitted betweenthese stages 30 and 31 and the partitions A and B while being positionedin the longitudinal direction. The sleeve 70 extending to the rear isfitted around the outer peripheral face of the input shaft 10 at therear end of the cylindrical part. The edge of the sleeve 70 is coupledwith the rear end of the rotor 25 and the rear end thereof is coupledwith the sun gear S0 of the power splitting planetary gear 21 throughthe inside of the second electric motor 23 described later. The sleeve70 is relatively and rotatably supported by the input shaft 10 throughthe intermediary of bearings d and x fixed to the outer peripheral faceof the input shaft 10 and the sun gear S0 is relatively and rotatablysupported by the input shaft 10 through an intermediary of a bearing yfixed to the outer peripheral face of the input shaft 10. It is noted asfor the disposition in the longitudinal direction that the bearing d isdisposed at the position corresponding to the bearings b and the bearingx is disposed at the position corresponding to the bearing g in thepartition C. The casing member 14 rotatably supports the both ends ofthe input shaft 10 through the intermediary of the bearing c between theinput shaft 10 and the rotor 25 provided at the position axiallyoverlapping with the bearing a and of the bearing a supporting the rotor25 at the front end thereof and through the intermediary of the bearingx provided between the input shaft 10 and the sleeve 10 provided at theposition axially overlapping with the bearing g, of the bearing Ibetween the sleeve 70 and the rotor 29 of the second electric motor 23and of the bearing g in the partition C supporting the rotor 29 of thesecond electric motor 23. Still more, a hollow cylindrical section isformed at the rear end of the input shaft 10, into which a boss sectionprojecting from the front end of a front end coupling section 12 b ofthe output shaft 12 is inserted. The bearing z is fitted between theinner peripheral face of the hollow cylindrical section and the outerperipheral face of the boss section. This bearing z supports the rearcarrier plate CR0 a of the carrier CR0 of the power splitting planetarygear 21 described later. Because the rotor 25 of the first electricmotor 20 is rotatably supported by the casing member 14 and the inputshaft 10 so as to be sandwiched by the bearings a and b fixed to thepartitions A and B and by the bearings c and d fixed to the outerperipheral face of the input shaft 10 as described above, the positionof the rotor 25 in the longitudinal and radial directions may be assuredaccurately. Accordingly, even if a force bending the casing member 14 inthe vertical or horizontal direction acts on the casing member 14, thepredetermined air gap G1 between the stator 24 and the rotor 25 may bekept accurately. It is noted that the first electric motor 20 isconnected to the HV battery via the inverter as described above. Themain function of the first electric motor 20 constructed as describedabove is to generate electricity and to charge the HV battery via theinverter based on the power split to the sun gear S0 of the powersplitting planetary gear 21 described later.

The second electric motor 23 comprises an AC permanent magnetsynchronous motor (brushless DC motor) for example and is disposed onthe outer diametric side of the input shaft 10 coaxially therewith. Thesecond electric motor 23 has the stator 28 fixed to the inner peripheralface of the casing member 14 and the rotor 29 rotatably disposed on theinner diametric side of the stator 28 apart from the stator 28 by apredetermined air gap G2. The inner diametric side of the rotor 29 isformed into a cylindrical shape and stages 48 and 50 are formed,respectively, at the front and rear outer peripheral faces of thecylindrical part. The casing member 14 rotatably supports the rotor 29through an intermediary of bearings f and g fitted between the stages 48and 50 and the partitions B and C while being positioned in thelongitudinal direction. The rear end of the cylindrical part is coupledwith the sun gear S1 of the transmission 22 described later via acoupling member 72. The coupling member 72 has a first sleeve portioncoupled with the rear end of the rotor 29, a first flange portionextending to the outer diametric side along the power splittingplanetary gear 21 from the rear end of the first sleeve portion, a drumportion extending to the rear from the outer diametric end of the firstflange portion, a second flange portion extending to the inner diametricside from the rear end of the drum portion and a second sleeve portionextending to the rear from the inner diametric end of the second flangeportion. The second sleeve portion is coupled with the sun gear S1. Therotor 29, the coupling member 72 and the sun gear S1 mutually formed ina body are rotatably supported by the bearings h and i fitted betweenthem and the outer peripheral face of the sleeve 70, the bearing jfitted between the coupling member 72 and the inner diametric rear faceof the partition C, the bearing 1 fitted between the coupling member 72and the inner diametric rear face of a flange portion 39 described laterand the bearings o and p fitted between the coupling member 72 and theouter peripheral face of the front end coupling section 12 b of theoutput shaft 12. It is noted that the bearings h and i are disposed atthe positions corresponding to the bearings f and g in terms of thedisposition in the longitudinal direction. Since the casing member 14rotatably supports the rotor 29 of the second electric motor 23 throughthe intermediary of the bearings f and g fixed to the partitions B and Cas described above, the longitudinal and radial positions of the rotor29 may be maintained accurately. Accordingly, even if a force that maybend the casing member 14 in the vertical or lateral direction actsthereon, the predetermined air gap G2 between the stator 28 and therotor 29 may be kept accurately. It is noted that the second electricmotor 23 is connected to the HV battery via the inverter similarly tothe first electric motor 20 described above.

The power splitting planetary gear 21 is disposed on the inner diametricside in the front half of the space between the partitions C and D ofthe casing member 14. The power splitting planetary gear 21 is composedof the single pinion planetary gear disposed coaxially with the inputshaft 10 as described above and has the ring gear (third rotary element)R0, the sun gear (second rotary element) S0 and the carrier (firstrotary element) CR0 supporting the pinions P0. Among them, the rear endof the ring gear R0 extends to the rear and is coupled with an outerdiametric end of a flange section 39 extending to the outer diametricside from the vicinity of the front end of the front end couplingportion 12 b of the output shaft 12 along the rear carrier CR0 a. Therear carrier plate CR0 a of the carrier CR0 is coupled with the rear endof the input shaft 10. The sun gear S0 is coupled with the rear end ofthe rotor 25 of the first electric motor 20 via the sleeve 70 describedabove. In the power splitting planetary gear 21, the bearing k is fittedbetween the inner diametric rear face of the rear carrier plate CR0 b ofthe carrier CR0 and the inner diametric front face of the flange section39 described above and the bearing 1 is fitted between the innerdiametric rear face of the flange section 39 and the coupling member 72described above, respectively. Thus, in the power splitting planetarygear 21, the carrier CR0, which is the input section, is fixed to theinput shaft 10 and the sun gear S0 and the ring gear R0, which are theoutput sections (to which power is split), are coupled with the rear endof the rotor 25 of the first electric motor 20 and with the front end ofthe front end coupling section 12 b of the output shaft 12,respectively. That is, the power splitting planetary gear 21 is arrangedso as to split the power of the internal combustion engine 5 inputted tothe carrier CR0 via the input shaft 10 (see FIG. 1) to the side of thefirst electric motor 20 via the sun gear S0 and to the side of theoutput shaft 12 via the ring gear R0. The ratio of split of power atthis time is decided based on the state of revolution of the firstelectric motor 20. That is, when the rotor 25 of the first electricmotor 20 is caused to generate a large power, an amount of powergenerated by the first electric motor 20 increases and the poweroutputted to the output shaft 12 is reduced to that extent. When therotor 25 of the first electric motor 20 is caused to generate a smallpower in contrary, an amount of power generated by the first electricmotor 20 decreases and the power outputted to the output shaft 12increases to that extent.

The transmission 22 is disposed on the rear half part and on the outerdiametric side of the front half part in the space between thepartitions C and D of the casing member 14. The transmission 22 has theRavigneaux type planetary gear unit 27 disposed on the inner diametricside and the first and second brakes B1 and B2 disposed, respectively,on the rear and front sides on the outer diametric side of the unit.

The planetary gear unit 27 has a first sun gear S1 (hereinafter simplyreferred to as ‘the sun gear S1’), a second sun gear S2 (hereinaftersimply referred to as ‘the sun gear S2’) disposed on the front side ofthe sun gear S1 and slightly on the outer diametric side, the ring gearR1 disposed on the outer diametric side of the sun gear S1, the pinionP1 engaging with the sun gear S1 and the ring gear R1, the pinion P2composing the common long pinion and engaging with the sun gear S2 andthe pinion P1, and the carrier CR1 supporting these pinions P1 and P2.Beginning from the sun gear S1, these parts will be explained below.

The sun gear S1 is coupled with the rear end of the rotor 29 of thesecond electric motor 23 described above via the sleeve 72described-above. Part of the sun gear S1 is rotatably supported throughan intermediary of the bearings o and p fitted to the outer peripheralface of the front end coupling section 12 b of the output shaft 12.

The sun gear S2 is formed in a body with the flange portion 34 extendingfrom the front end of the sun gear S2 to the outer diametric side alongthe front carrier plate CR1 b of the carrier CR1 and with the drumportion 35 extending to the rear from the outer diametric end of theflange portion 34. The second brake B2 described later is interposedbetween the outer peripheral face of this drum portion 35 and the innerperipheral spline 14 a of the inner peripheral face of the casing member14. The sun gear S2 is rotatably supported by bearings q and r fitted tothe outer peripheral face of the second sleeve portion of the couplingmember 72 formed in a body with the sun gear S1 described above andbearings m and n fitted, respectively, to the front and rear faces onthe inner diametric side (basal end side) of the flange portion 34. Itis noted that the bearing m is interposed between the flange portion 34and the coupling member 72 and the bearing n is interposed between theflange portion 34 and the inner diametric front face of the frontcarrier plate CR1 b of the carrier CR1.

The ring gear R1 is provided with the flange portion 36 fixed at therear end thereof and extending to the inner diametric side along therear carrier plate CR1 a of the carrier CR1 and is rotatably supportedby bearings t and u fitted to the inner diametric front and rear facesof the flange portion 36. The bearing t is interposed between the flangeportion 36 and the rear carrier plate CR1 a of the carrier CR1 and thebearing u is interposed between the flange portion 36 and the partitionD. The first brake B1 is interposed between the outer peripheral face ofthe ring gear R1 and the inner peripheral spline 14 a of the innerperipheral face of the casing member 14.

The pinion P1 is rotatably supported by the carrier CR1 and is engagedwith the sun gear S1 described above on the inner diametric side andwith the ring gear R1 described above on the outer diametric side.

The pinion P2 is the common long pinion in which the large-diametricgear P2 a formed on the front side and the small-diametric gear P2 bformed on the rear side are combined in a body. In the pinion P2, thelarge-diametric gear P2 a is engaged with the sun gear S2 describedabove and the small-diametric gear P2 b is engaged with the pinion P1described above.

The carrier CR1 rotatably supports the pinions P1 and P2 by the frontand rear carrier plates CR1 b and CR1 a. The rear carrier plate CR1 a iscoupled with the front end of the output shaft 12. The rear carrierplate CR1 a is rotatably supported by the bearing s fitted between theinner diametric front face thereof and the rear end face of the sun gearS1 and the bearing t described above.

The first brake B1 has a number of discs and friction plates (brakeplates) and is spline-coupled between an outer peripheral spline formedon the outer peripheral face of the ring gear R1 described above and theinner peripheral spline 14 a formed on the inner peripheral face of thecasing member 14. A hydraulic actuator 37 for the first brake isdisposed on the rear side of the first brake B1. The hydraulic actuator37 has the piston 38 disposed on the rear side of the first brake B1 soas to be movable in the longitudinal direction, the first hydraulicchamber 40 which is provided at the outer diametric front face of thepartition D of the casing member 14 and into which the rear end of thepiston 38 is oil-tightly fitted and the return spring (compressionspring) 42 interposed between the retainer 41 fixed to a part of thepartition D and the inner diametric front face of the piston 38 to biasthe piston 38 to the rear.

The second brake B2 is disposed just before the first brake B1 describedabove. The second brake B2 has a number of discs and friction plates(brake plates) and is spline-coupled between the outer peripheral splineformed on the outer peripheral face of the drum portion 35 combined withthe sun gear S2 described above and the inner spline 14 a formed on theinner peripheral face of the casing member 14. The hydraulic actuator 43for the second brake is disposed on the front side of the second brakeB2 so that it is positioned on the outer diametric side of the powersplitting planetary gear 21 described above. The hydraulic actuator 43has the piston 44 disposed on the front side of the second brake B2 soas to be movable in the longitudinal direction, the second hydraulicchamber 45 which is provided at the outer diametric rear face of thepartition C and into which the front end of the piston 44 is oil-tightlyfitted, and the return spring (compression spring) 47 interposed betweenthe retainer 46 fixed to the inner peripheral face of the casing member14 and a part of the piston 44 to bias the piston 44 to the front.

In the transmission 22 constructed as described above, an output fromthe second electric motor 23 is transmitted to the sun gear S1 via thecoupling member 72. In a low state, the first brake B1 is engaged andthe second brake B2 is released. Accordingly, the ring gear R1 is lockedand the sun gear S2 is freely rotatable in this state. The revolution ofthe first sun gear S1 described above is largely reduced via the pinionP1 and is transmitted to the carrier CR1. The revolution of the carrierCR1 is then transmitted to the output shaft 12.

When the transmission 22 is in a high state, the first brake B1 isreleased and the second brake B2 is engaged. Accordingly, the sun gearS2 is locked and the ring gear R1 is freely rotatable in this state. Inthis state, the revolution of the sun gear S1 is transmitted to thepinion P1 and the pinion P2 engages with the locked sun gear S2. Then,the carrier CR1 moves around the sun gear at a restricted predeterminednumber of revolution and the revolution of the carrier CR1 reducedrelatively in small is transmitted to the output shaft 12 at this time.

Thus, the transmission 22 transmits the largely reduced revolution tothe output shaft 12 in the low state by engaging the first brake B1 andby releasing the second brake B2, respectively. In contrary, ittransmits the revolution reduced relatively in small to the output shaft12 by releasing the first brake B1 and by engaging the second brake B2,respectively. Because the transmission 22 is thus capable of shifting inthe two stages, the second electric motor 23 maybe downsized. That is,the transmission 22 enables to use a small electric motor, to transmitsufficient driving torque to the output shaft 12 in the low state instarting the vehicle 1 when high torque is required, and to prevent therotor 29 from rotating at high-speed by putting it in the high statewhen the output shaft 12 is rotating at high-speed.

The casing member 14 storing the first electric motor 20, the secondelectric motor 23, the power splitting planetary gear 21 and thetransmission 22 as described above has a boss section 14 b extending tothe rear on the inner diametric side of the rearmost partition D androtatably supports the output shaft 12 by the boss section 14 b throughan intermediary of bearings v and w.

The coupling section 14 d at the front end of the casing member 14 isconnected with the internal combustion engine 5 rubber-mounted to thebody 4 (see FIG. 1) and the rear end thereof is rubber-mounted to a partof the body by utilizing the mounting section not shown.

In the hybrid driving unit 7B constructed as described above, the motivepower inputted to the input shaft 10 is inputted to the carrier CR0 ofthe power splitting planetary gear 21 to be split (divided) to the sungear S0 and the ring gear R0 as shown in the skeleton view of FIG. 7.Among them, the motive power split to the sun gear S0 is inputted to therotor 25 of the first electric motor 20 to be used to generateelectricity. The electricity thus generated is charged to the HV batteryvia the inverter. The second electric motor 23 receives the electricitysupplied from the HV battery via the inverter and drives the outputshaft 12 via the transmission 22. That is, the motive power from theinternal combustion engine 5 is combined with the power from the secondelectric motor 23 and is outputted to the output shaft 12. It is notedthat because the transmission 22 is arranged so as to be capable ofswitching between the high and low states as described above, powercorresponding to the high or low state is outputted to the output shaft12.

Since the first electric motor 20 and the second electric motor 23 aredisposed adjacently to each other on the axis 13 as shown in FIG. 8 inthe present embodiment, the parts of the case storing these first andsecond electric motors 20 and 23 may be combined, thus facilitating theaccommodation in producing the unit in series. It also brings about sucheffects that a number of parts and, hence the cost, may be reduced, theaccuracy for supporting the two electric motors 20 and 23 may beimproved, the length of power cables of the two electric motors 20 and23 may be almost equalized regardless of the position of the controllerfor controlling them, the length of the cable may be minimized when theinverter is disposed within an engine room on the front side of thevehicle, thus minimizing the loss of electricity, and others.

Next, a first modification (corresponding to the 16-th aspect of theinvention) of the hybrid driving unit 7B of the present embodiment willbe explained with reference to a skeleton view in FIG. 9.

As shown in FIG. 9, the hybrid driving unit 7B has the first electricmotor 20, the second electric motor 23, the power splitting planetarygear 21 and the transmission 22 in order from the side closer to theinternal combustion engine 5 in FIG. 1, i.e., in order from the front tothe rear. All of these are stored within the casing member 14 (see FIG.1) and are disposed in line around the axis 13 in order from the front.These devices will be explained below in the order of the first electricmotor 20, the second electric motor 23, the power splitting planetarygear 21 and the transmission 22.

The first electric motor 20 has the stator 24 fixed to the casing member14 (see FIG. 1) and the rotor 25 rotatably supported on the innerdiametric side of the stator 24. The rotor 25 of the first electricmotor 20 is coupled with the ring gear R0 of the power splittingplanetary gear 21 described later. The first electric motor 20constructed as described above mainly generates electricity based on themotive power inputted via the ring gear R0 and drives the secondelectric motor 23 or charges the HV battery (hybrid driving battery) notshown via the inverter not shown.

The second electric motor 23 has the stator 28 fixed to the casingmember 14 (see FIG. 1) and the rotor 29 rotatably supported on the innerdiametric side of the stator 28. The rotor 29 of the second electricmotor 23 is coupled with the sun gear S1 of the transmission 22described later. Similarly to the first electric motor 20 describedabove, the second electric motor 23 is connected to the HV battery viathe inverter. The second electric motor 23 functions mainly as a drivingmotor for assisting the motive power of the vehicle 1. However, thesecond electric motor 23 also functions as a generator when the brake isapplied to the vehicle for example by regenerating vehicular inertiaforce as electrical energy.

The power splitting planetary gear 21 is composed of the single pinionplanetary gear disposed coaxially with the output shaft 12. The powersplitting planetary gear 21 has the carrier (first rotary element) CR0supporting a plurality of pinions P0, the sun gear (third rotaryelement) S0 engaging with the pinion P0 and the ring gear (second rotaryelement) R0 engaging with the pinion P0. The carrier CR0 of the powersplitting planetary gear 21 is coupled with the input shaft 10, the ringgear R0 is coupled with the rotor 25 of the first electric motor 20 andthe sun gear S0 is coupled with the output shaft 12. The power splittingplanetary gear 21 constructed as described above splits the motive powerinputted to the carrier CR0 via the input shaft 10 to the first electricmotor 20 via the ring gear R0 and to the output shaft 12 via the sungear S0 based on the control on the revolution of the first electricmotor 20. It is noted that the power split to the first electric motor20 is used for generating electricity and the power split to the outputshaft 12 is used for driving the vehicle 1.

The transmission 22 has the so-called Ravigneaux type planetary gearunit 27 comprising one double pinion planetary gear and the singleplanetary gear that uses one of their pinions in common. Thetransmission 22 also has the first and second brakes B1 and B2.

The planetary gear unit 27 is composed of the two sun gears S1 and S2,the carrier CR1 supporting the pinion P1 and the pinion (common longpinion) P2, and the ring gear R1. Among the two pinions P1 and P2, thepinion P1 engages with the sun gear S1 and the ring gear R1, and thepinion P2, i.e., the common long pinion, engages with the sun gear S2and the pinion P1. The ring gear R1 of the planetary gear unit 27 iscoupled with the first brake B1 and the sun gear S2 is coupled with thesecond brake B2. As a whole, the sun gear S1, which is an input member(input element), is coupled with the rotor 29 of the second electricmotor 23 described above, and the carrier CR1, which is an output member(output element), is coupled with the output shaft 12. This transmission22 is arranged so as to be able to change two deceleration stages whosereduction ratios are different by engaging one of the first and secondbrakes B1 and B2 while releasing the other and by releasing the onewhile engaging the other. That is, the transmission 22 is arranged so asto change the degree of the motive power inputted from the secondelectric motor 23 described above via the sun gear S1 and to transmit itto the output shaft 12 via the carrier CR1.

In the hybrid driving unit 7B shown in FIG. 9, among the four devices ofthe first electric motor 20, the second electric motor 23, the powersplitting planetary gear 21 and the transmission 22, the former twodevices are disposed on the input shaft 10 and the remaining two devicesare disposed on the output shaft 12. These are coupled each other asfollows as shown in the figure.

The input shaft 10 is coupled with the front side (the side of thesecond electric motor 23) of the carrier (first rotary element) CR0 ofthe power splitting planetary gear 21 through the inner peripheral sideof the first electric motor 20 and the second electric motor 23. Theoutput shaft 12 is coupled with the carrier (output element) CR1 of thetransmission 22 as well as to the sun gear (third rotary element) S0 ofthe power splitting planetary gear 21 through the inner peripheral sideof the transmission 22. The rotor 25 of the first electric motor 20 iscoupled with the ring gear (second rotary element) R0 of the powersplitting planetary gear 21 through the parts between the outerperipheral side of the input shaft 10 and the inner peripheral side ofthe second electric motor 23 and between the second electric motor 23and the power splitting planetary gear 21. Then, the rotor 29 of thesecond electric motor 23 is coupled with the sun gear (input element) S1through between the second electric motor 23 and the power splittingplanetary gear 21, the outer peripheral side of the power splittingplanetary gear 21, the part between the power splitting planetary gear21 and the transmission 22 and the inner peripheral side of the sun gearS2 of the transmission 22.

Next, a second modification (corresponding to the 17-th aspect of theinvention) of the hybrid driving unit 7B of the present embodiment willbe explained with reference to a skeleton view in FIG. 10.

As shown in FIG. 10, the hybrid driving unit 7B comprises the firstelectric motor 20, the second electric motor 23, the power splittingplanetary gear 21 and the transmission 22 in order from the side closerto the internal combustion engine 5 in FIG. 1, i.e., in order from thefront to the rear. All of these are stored within the casing member 14(see FIG. 1) and are disposed in line around the axis 13 in order fromthe front along the axis 13. These devices will be explained below inthe order of the first electric motor 20, the second electric motor 23,the power splitting planetary gear 21 and the transmission 22.

The first electric motor 20 has the stator 24 fixed to the casing member14 (see FIG. 1) and the rotor 25 rotatably supported on the innerdiametric side of the stator 24. The rotor 25 of the first electricmotor 20 is coupled with the carrier CR0 of the power splittingplanetary gear 21 described later. The first electric motor 20 arrangedas described above mainly generates electricity based on the motivepower inputted via the carrier CR0 and drives the second electric motor23 or charges the HV battery (hybrid driving battery) not shown via theinverter not shown.

The second electric motor 23 has the stator 28 fixed to the casingmember 14 (see FIG. 1) and the rotor 29 rotatably supported on the innerdiametric side of the stator 28. The rotor 29 of the second electricmotor 23 is coupled with the sun gear S1 of the transmission 22described later. Similarly to the first electric motor 20 describedabove, the second electric motor 23 is connected to the HV battery viathe inverter. The second electric motor 23 functions mainly as a drivingmotor for assisting the motive power (driving force) of the vehicle 1.However, the second electric motor 23 also functions as a generator whenthe brake is applied to the vehicle for example by regeneratingvehicular inertia force as electrical energy.

The power splitting planetary gear 21 is composed of the double pinionplanetary gear disposed coaxially with the input shaft 10. The powersplitting planetary gear 21 has the carrier (second rotary element) CR0supporting the plurality of pinions P0 (P01 and P02), the sun gear(third rotary element) S0 engaging with the pinion P1 and the ring gear(first rotary element) R0 engaging with the pinion P02. The ring gear R0of the power splitting planetary gear 21 is coupled with the input shaft10, the carrier CR0 is coupled with the rotor 25 of the first electricmotor 20 and the sun gear S0 is coupled with the output shaft 12. Thepower splitting planetary gear 21 described above splits the motivepower inputted to the ring gear R0 via the input shaft 10 to the firstelectric motor 20 via the carrier CR0 and to the output shaft 12 via thesun gear S0 based on the control on the revolution of the first electricmotor 20. It is noted that the power split to the first electric motor20 is used for generating electricity and the power split to the outputshaft 12 is used for driving the vehicle 1.

The transmission 22 has the so-called Ravigneaux type planetary gearunit 27 comprising one double pinion planetary gear and the singleplanetary gear that uses one of their pinions in common. Thetransmission 22 also has the first and second brakes B1 and B2.

The planetary gear unit 27 is composed of the two sun gears S1 and S2,the carrier CR1 supporting the pinion P1 and the pinion (common longpinion) P2, and the ring gear R1. Among the two pinions P1 and P2, thepinion P1 engages with the sun gear S1 and the ring gear R1, and thepinion P2, i.e., the common long pinion, engages with the sun gear S2and the pinion P1. The ring gear R1 of the planetary gear unit 27 iscoupled with the first brake B1 and the sun gear S2 is coupled with thesecond brake B2. As a whole, the sun gear S1, which is the input member(input element), is coupled with the rotor 29 of the second electricmotor 23 described above, and the carrier CR1, which is the outputmember (output element), is coupled with the output shaft 12. Thistransmission 22 is arranged so as to be able to change two decelerationstages whose reduction ratios are different by engaging one of the firstand second brakes B1 and B2 while releasing the other and by releasingthe one while engaging the other as described later. That is, thetransmission 22 is arranged so as to change the degree of the motivepower inputted from the second electric motor 23 described above via thesun gear S1 and to transmit it to the output shaft 12 via the carrierCR1.

In the hybrid driving unit 7B shown in FIG. 10, the front three devicesamong the four devices of the first electric motor 20, the secondelectric motor 23, the power splitting planetary gear 21 and thetransmission 22 are disposed on the input shaft 10 and the remaining onedevice is disposed on the output shaft 12. These are coupled each otheras follows as shown in the figure.

The input shaft 10 is coupled with the ring gear (first rotary element)R0 of the power splitting planetary gear 21 through the inner peripheralside of the first electric motor 20, the second electric motor 23 andthe power splitting planetary gear 21 and the part between the powersplitting planetary gear 21 and the transmission 22. The output shaft 12is coupled with the carrier (output element) CR1 of the transmission 22as well as to the sun gear (third rotary element) S0 of the powersplitting planetary gear 21 through the inner peripheral side of thetransmission 22, the part between the transmission 22 and the powersplitting planetary gear 21, the outer peripheral side of the powersplitting planetary gear 21 and the part between the power splittingplanetary gear 21 and the second electric motor 23. The rotor 25 of thefirst electric motor 20 is coupled with the rear side (transmissionside) of the carrier (second rotary element) CR0 of the power splittingplanetary gear 21 through the outer peripheral side of the input shaft10 and the inner peripheral side of the second electric motor 23 and thepower splitting planetary gear 21. Then, the rotor 29 of the secondelectric motor 23 is coupled with the sun gear (input element) S1through between the second electric motor 23 and the power splittingplanetary gear 21, the outer peripheral side of the power splittingplanetary gear 21, the part between the power splitting planetary gear21 and the transmission 22 and the inner peripheral side of the sun gearS2 of the transmission 22.

Next, a third modification (corresponding to the 18-th aspect of theinvention) of the hybrid driving unit 7B of the present embodiment willbe explained with reference to a skeleton view in FIG. 11.

As shown in FIG. 11, the hybrid driving unit 7B comprises the firstelectric motor 20, the second electric motor 23, the power splittingplanetary gear 21 and the transmission 22 in order from the side closerto the internal combustion engine 5 in FIG. 1, i.e., in order from thefront to the rear. All of these are stored within the casing member 14(see FIG. 1) and are disposed in line around the axis 13 in order fromthe front along the axis 13. These devices will be explained below inthe order of the first electric motor 20, the second electric motor 23,the power splitting planetary gear 21 and the transmission 22.

The first electric motor 20 has the stator 24 fixed to the casing member14 (see FIG. 1) and the rotor 25 rotatably supported on the innerdiametric side of the stator 24. The rotor 25 of the first electricmotor 20 is coupled with the sun gear S0 of the power splittingplanetary gear 21 described later. The first electric motor 20 mainlygenerates electricity based on the motive power inputted via the sungear S0 and drives the second electric motor 23 or charges the HVbattery (hybrid driving battery) not shown via the inverter not shown.

The second electric motor 23 has the stator 28 fixed to the casingmember 14 (see FIG. 1) and the rotor 29 rotatably supported on the innerdiametric side of the stator 28. The rotor 29 of the second electricmotor 23 is coupled with the sun gear S1 of the transmission 22described later. Similarly to the first electric motor 20 describedabove, the second electric motor 23 is connected to the HV battery viathe inverter. The second electric motor 23 mainly functions as a drivingmotor for assisting the motive power (driving force) of the vehicle 1.However, the second electric motor 23 also functions as a generator whenthe brake is applied to the vehicle for example by regeneratingvehicular inertia force as electrical energy.

The power splitting planetary gear 21 is composed of the double pinionplanetary gear disposed coaxially with the input shaft 10. The powersplitting planetary gear 21 has the carrier (first rotary element) CR0supporting the plurality of pinions P0 (P01 and P02), the sun gear(second rotary element) S0 engaging with the pinion P01 and the ringgear (third rotary element) R0 engaging with the pinion P02. The carrierCR0 of the power splitting planetary gear 21 is coupled with the inputshaft 10, the sun gear S0 is coupled with the rotor 25 of the firstelectric motor 20 and the ring gear R0 is coupled with the output shaft12. The power splitting planetary gear 21 constructed as described abovesplits the motive power inputted to the carrier CR0 via the input shaft10 to the first electric motor 20 via the sun gear S0 and to the outputshaft 12 via the ring gear R0 based on the control on the revolution ofthe first electric motor 20. It is noted that the power split to thefirst electric motor 20 is used for generating electricity and the powersplit to the output shaft 12 is used for driving the vehicle 1.

The transmission 22 has the so-called Ravigneaux type planetary gearunit 27 composed of one double pinion planetary gear and the singleplanetary gear that uses one of their pinions in common. Thetransmission 22 also has the first and second brakes B1 and B2.

The planetary gear unit 27 is composed of the two sun gears S1 and S2,the carrier CR1 supporting the pinion P1 and the pinion (common longpinion) P2, and the ring gear R1. Among the two pinions P1 and P2, thepinion P1 engages with the sun gear S1 and the ring gear R1, and thepinion P2, i.e., the common long pinion, engages with the sun gear S2and the pinion P1. The ring gear R1 of the planetary gear unit 27 iscoupled with the first brake B1 and the sun gear S2 is coupled with thesecond brake B2. As a whole, the sun gear S1, which is an input member(input element), is coupled with the rotor 29 of the second electricmotor 23 described above, and the carrier CR1, which is an output member(output element), is coupled with the output shaft 12. This transmission22 is arranged so as to be able to change two deceleration stages whosereduction ratios are different by engaging one of the first and secondbrakes B1 and B2 while releasing the other and by releasing the onewhile engaging the other as described later. That is, the transmission22 is arranged so as to change the degree of the motive power inputtedfrom the second electric motor 23 described above via the carrier CR1and to transmit it to the output shaft 12 via the carrier CR1.

In the hybrid driving unit 7B shown in FIG. 11, the front three devicesof the four devices of the first electric motor 20, the second electricmotor 23, the power splitting planetary gear 21 and the transmission 22are disposed on the input shaft 10 and the rearmost one is disposed onthe output shaft 12. These are coupled each other as follows as shown inthe figure.

The input shaft 10 is coupled with the rear side (the transmission 22side) of the carrier (first rotary element) CR0 of the power splittingplanetary gear 21 through the inner peripheral side of the firstelectric motor 20, the second electric motor 23 and the power splittingplanetary gear 21. The output shaft 12 is coupled with the carrier(output element) CR1 of the transmission 22 as well as with the ringgear (third rotary element) R0 of the power splitting planetary gear 21through the inner peripheral side of the power splitting planetary gear21 and between the transmission 22 and the power splitting planetarygear 2l. The rotor 25of the first electric motor 20 is coupled with thesun gear (second rotary element) S0 of the power splitting planetarygear 21 through between the outer peripheral side of the input shaft 10and the inner peripheral side of the second electric motor 23. Then, therotor 29 of the second electric motor 23 is coupled with the sun gear(input element) S1 through between the second electric motor 23 and thepower splitting planetary gear 21, the outer peripheral side of thepower splitting planetary gear 21, the part between the power splittingplanetary gear 21 and the transmission 22 and the inner peripheral sideof the sun gear S2 of the transmission 22.

Third Embodiment

Next, a hybrid driving unit 7C of a third embodiment will be explainedas another example of the inventive hybrid driving unit 7 mounted to thevehicle 1 shown in FIG. 1 with reference to the skeleton view in FIG.12. It is noted that in the figure, the direction indicated by the arrowF denotes the front side of the body (the internal combustion engineside) and the direction indicated by the arrow R denotes the rear sidethereof (the differential unit side).

As shown in FIG. 12, the hybrid driving unit 7C comprises the powersplitting planetary gear 21 the first electric motor 20, the secondelectric motor 23 and the transmission 22 in order from the side closerto the internal combustion engine 5 in FIG. 1, i.e., in order from thefront to the rear. All of these are stored within the casing member 14(see FIG. 1) and are disposed in line around the axis 13 in order fromthe front along the axis 13. These devices will be explained below inthe order of the power splitting planetary gear 21, the first electricmotor 20, the second electric motor 23 and the transmission 22.

The power splitting planetary gear 21 is composed of the double pinionplanetary gear disposed coaxially with the output shaft 12. The powersplitting planetary gear 21 has the carrier (third rotary element) CR0supporting the plurality of pinions P0, the sun gear (second rotaryelement) S0 engaging with the pinion P01 and the ring gear (first rotaryelement) R0 engaging with the pinion P02. The ring gear r0 of the powersplitting planetary gear 21 is coupled with the input shaft 10, the sungear S0 is coupled with the rotor 25 of the first electric motor 20 andthe carrier CR0 is coupled with the output shaft 12. The power splittingplanetary gear 21 constructed as described above splits the motive powerinputted to the ring gear R0 via the input shaft 10 to the firstelectric motor 20 via the sun gear S0 and to the output shaft 12 via thering gear R0 based on the control on the revolution of the firstelectric motor 20. It is noted that the power split to the firstelectric motor 20 is used for generating electricity and the power splitto the output shaft 12 is used for driving the vehicle 1.

The first electric motor 20 has the stator 24 fixed to the casing member14 (see FIG. 1) and the rotor 25 rotatably supported on the innerdiametric side of the stator 24. The rotor 25 of the first electricmotor 20 is coupled with the sun gear S0 of the power splittingplanetary gear 21 described later. The first electric motor 20constructed as described above mainly generates electricity based on themotive power inputted via the sun gear S0 and drives the second electricmotor 23 or charges the HV battery (hybrid driving battery) not shownvia the inverter not shown.

The second electric motor 23 has the stator 28 fixed to the casingmember 14 (see FIG. 1) and the rotor 29 rotatably supported on the innerdiametric side of the stator 28. The rotor 29 of the second electricmotor 23 is coupled with a sun gear S1 of the transmission 22 describedlater. Similarly to the first electric motor 20 described above, thesecond electric motor 23 is connected to the HV battery via theinverter. The second electric motor 23 functions mainly as a drivingmotor for assisting the motive power (driving force) of the vehicle 1.However, the second electric motor 23 also functions as a generator whenthe brake is applied to the vehicle for example by regeneratingvehicular inertia force as electrical energy.

The transmission 22 has the so-called Ravigneaux type planetary gearunit 27 composed of one double pinion planetary gear and the singleplanetary gear that uses one of their pinions in common. Thetransmission 22 also has the first and second brakes B1 and B2.

The planetary gear unit 27 is composed of two sun gears S1 and S2, thecarrier CR1 supporting the pinion P1 and the pinion (common long pinion)P2, and the ring gear R1. Among the two pinions P1 and P2, the pinion P1engages with the sun gear S1 and the ring gear R1, and the pinion P2,i.e., the common long pinion, engages with the sun gear S2 and thepinion P1. The ring gear R1 of the planetary gear unit 27 is coupledwith the first brake B1 and the sun gear S2 is coupled with the secondbrake B2. As a whole, the sun gear S1, which is an input member (inputelement), is coupled with the rotor 29 of the second electric motor 23described above, and the carrier CR1, which is an output member (outputelement), is coupled with the output shaft 12. This transmission 22 isarranged so as to be able to change two deceleration stages whosereduction ratios are different by engaging one of the first and secondbrakes B1 and B2 while releasing the other and by releasing the onewhile engaging the other. That is, the transmission 22 is arranged so asto change the degree of the motive power inputted from the secondelectric motor 23 described above via the sun gear S1 and to transmit itto the output shaft 12 via the carrier CR1.

In the transmission 22 constructed as described above, the first brakeB1 is engaged and the second brake B2 is released in the low state.Accordingly, the ring gear R1 is locked and the sun gear S2 is freelyrotatable in this state. The revolution of the first sun gear S1described above is largely reduced via the pinion P1 and is transmittedto the carrier CR1. The revolution of the carrier CR1 is thentransmitted to the output shaft 12.

When the transmission 22 is in the high state, the first brake B1 isreleased and the second brake B2 is engaged. Accordingly, the sun gearS2 is locked and the ring gear RI is freely rotatable in this state. Inthis state, the revolution of the sun gear S1 is transmitted to thepinion P1 and the pinion P2 engages with the locked sun gear S2. Then,the carrier CR1 moves around the sun gear at a restricted predeterminednumber of revolution and the revolution of the carrier CR1 reducedrelatively in small is transmitted to the output shaft 12 at this time.

Thus, the transmission 22 transmits the largely reduced revolution tothe output shaft 12 in the low state by engaging the first brake B1 andby releasing the second brake B2, respectively. In contrary, ittransmits the revolution reduced relatively in small to the output shaft12 by releasing the first brake B1 and by engaging the second brake B2,respectively. Because the transmission 22 is thus capable of shifting inthe two stages, the second electric motor 23 may be downsized. That is,the transmission 22 enables to use a small electric motor, to transmitsufficient driving torque to the output shaft 12 in the low state instarting the vehicle 1 when high torque is required, and to prevent therotor 29 from rotating at high-speed by putting it in the high statewhen the output shaft 12 is rotating at high-speed.

In the hybrid driving unit 7C shown in FIG. 12, all of the four devicesof the power splitting planetary gear 21, the first electric motor 20,the second electric motor 23 and the transmission 22 are disposed on theoutput shaft 12. These are coupled each other as follows as shown in thefigure.

The input shaft 10 is coupled with the ring gear (first rotary element)R0 of the power splitting planetary gear 21. The output shaft 12 iscoupled with the carrier (output element) CR1 of the transmission 22 andwith the front side of the carrier (third rotary element) CR0 of thepower splitting planetary gear 21 through the inner peripheral side ofthe transmission 22, the second electric motor 23, the first electricmotor 20 and the power splitting planetary gear 21. The rotor 25 of thefirst electric motor 20 is coupled with the sun gear (second rotaryelement) S0 of the power splitting planetary gear 21. Then, the rotor 29of the second electric motor 23 is coupled with the sun gear (inputelement) S1 through the outer peripheral side of the output shaft 12.

In the hybrid driving unit 7C constructed as described above, the motivepower inputted to the input shaft 10 is inputted to the ring gear R0 ofthe power splitting planetary gear 21 to be split (divided) to the sungear S0 and the carrier CR0 as shown in the skeleton view of FIG. 12.Among them, the motive power split to the sun gear S0 is inputted to therotor 25 of the first electric motor 20 to be used to generateelectricity. The electricity thus generated is charged to the HV batteryvia the inverter. The second electric motor 23 receives the electricitysupplied from the HV battery via the inverter and drives the outputshaft 12 via the transmission 22. That is, the motive power from theinternal combustion engine 5 is combined with the power from the secondelectric motor 23 and is outputted to the output shaft 12. It is notedthat because the transmission 22 is arranged so as to be capable ofswitching between the high and low states as described above, powercorresponding to the high or low state is outputted to the output shaft12.

Since the first electric motor 20 and the second electric motor 23 aredisposed adjacently to each other on the axis 13 as shown in FIG. 12 inthe present embodiment, the parts of the case storing these first andsecond electric motors 20 and 23 may be combined, thus facilitating theaccommodation in producing the unit in series. It also brings about sucheffects that a number of parts and, hence the cost, may be reduced, theaccuracy for supporting the two electric motors 20 and 23 may beimproved, the length of power cables of the two electric motors 20 and23 may be almost equalized regardless of the position of the controllerfor controlling them, the length of the cable may be minimized when theinverter is disposed within an engine room on the front side of thevehicle, thus minimizing the loss of electricity, and others.

Fourth Embodiment

Next, a hybrid driving unit 7D of a fourth embodiment will be explainedas another example of the inventive hybrid driving unit 7 mounted to thevehicle 1 shown in FIG. 1 with reference to the skeleton view in FIG.13. It is noted that in the figure, the direction indicated by the arrowF denotes the front side of the body (the internal combustion engineside) and the direction indicated by the arrow R denotes the rear sidethereof (the differential unit side).

As shown in FIG. 13, the hybrid driving unit 7D comprises thetransmission 22, the second electric motor 23, the first electric motor20 and the power splitting planetary gear 21 in order from the sidecloser to the internal combustion engine 5 in FIG. 1, i.e., in orderfrom the front to the rear. All of these are stored within the casingmember 14 (see FIG. 1) and are disposed in line around the axis 13 inorder from the front along the axis 13. These devices will be explainedbelow in the order of the transmission 22, the second electric motor 23,the first electric motor 20 and the power splitting planetary gear 21.

The transmission 22 has the so-called Ravigneaux type planetary gearunit 27 composed of one double pinion planetary gear and the singleplanetary gear that uses one of their pinions in common. Thetransmission 22 also has the first and second brakes B1 and B2.

The planetary gear unit 27 is composed of the two sun gears S1 and S2,the carrier CR1 supporting the pinion P1 and the pinion (common longpinion) P2, and the ring gear R1. Among the two pinions P1 and P2, thepinion P1 engages with the sun gear S1 and the ring gear R1, and thepinion P2, i.e., the common long pinion, engages with the sun gear S2and the pinion P1. The ring gear R1 of the planetary gear unit 27 iscoupled with the first brake B1 and the sun gear S2 is coupled with thesecond brake B2. As a whole, the sun gear S1, which is an input member(input element), is coupled with the rotor 29 of the second electricmotor 23 described later, and the carrier CR1, which is an output member(output element), is coupled with the output shaft 12 via the carrierCR0 of the power splitting planetary gear 21 described later. Thistransmission 22 is arranged so as to be able to change two decelerationstages whose reduction ratios are different by engaging one of the firstand second brakes B1 and B2 while releasing the other and by releasingthe one while engaging the other. That is, the transmission 22 isarranged so as to change the degree of the motive power inputted fromthe second electric motor 23 described above via the sun gear S1 and totransmit it to the output shaft 12 via the carrier CR1.

In the transmission 22 constructed as described above, the first brakeB1 is engaged and the second brake B2 is released in the low state.Accordingly, the ring gear R1 is locked and the sun gear S2 is freelyrotatable in this state. The revolution of the first sun gear S1described above is largely reduced via the pinion P1 and is transmittedto the carrier CR1. The revolution of the carrier CR1 is thentransmitted to the output shaft 12.

When the transmission 22 is in the high state, the first brake B1 isreleased and the second brake B2 is engaged. Accordingly, the sun gearS2 is locked and the ring gear R1 is freely rotatable in this state. Inthis state, the revolution of the sun gear S1 is transmitted to thepinion P1 and the pinion P2 engages with the locked sun gear S2. Then,the carrier CR1 moves around the sun gear at a restricted predeterminednumber of revolution and the revolution of the carrier CR1 reducedrelatively in small is transmitted to the output shaft 12 at this time.

Thus, the transmission 22 transmits the largely reduced revolution tothe output shaft 12 in the low state by engaging the first brake B1 andby releasing the second brake B2, respectively. In contrary, ittransmits the revolution reduced relatively in small to the output shaft12 by releasing the first brake B1 and by engaging the second brake B2,respectively. Because the transmission 22 is thus capable of shifting inthe two stages, the second electric motor 23 may be downsized. That is,the transmission 22 enables to use a small electric motor, to transmitsufficient driving torque to the output shaft 12 in the low state instarting the vehicle 1 when high torque is required, and to prevent therotor 29 from rotating at high-speed by putting it in the high statewhen the output shaft 12 is rotating at high-speed.

The second electric motor 23 has the stator 28 fixed to the casingmember 14 (see FIG. 1) and the rotor 29 rotatably supported on the innerdiametric side of the stator 28. The rotor 29 of the second electricmotor 23 is coupled with a sun gear S1 of the transmission 22 describedabove. Similarly to the first electric motor 20 described above, thesecond electric motor 23 is connected to the HV battery via theinverter. The second electric motor 23 functions mainly as a drivingmotor for assisting the motive power (driving force) of the vehicle 1.However, it also functions as a generator when the brake is applied tothe vehicle for example by regenerating vehicular inertia force aselectrical energy.

The first electric motor 20 has the stator 24 fixed to the casing member14 (see FIG. 1) and the rotor 25 rotatably supported on the innerdiametric side of the stator 24. The rotor 25 of the first electricmotor 20 is coupled with the sun gear S0 of the power splittingplanetary gear 21 described later. The first electric motor 20constructed as described above mainly generates electricity based on themotive power inputted via the sun gear S0 and drives the second electricmotor 23 or charges the HV battery (hybrid driving battery) not shownvia the inverter not shown.

The power splitting planetary gear 21 is composed of the double pinionplanetary gear disposed coaxially with the input shaft 10. The powersplitting planetary gear 21 has the carrier (third rotary element) CR0supporting the plurality of pinions P0, the sun gear (second rotaryelement) S0 engaging with the pinion P01 and the ring gear (first rotaryelement) R0 engaging with the pinion P02. The ring gear r0 of the powersplitting planetary gear 21 is coupled with the input shaft 10, the sungear S0 is coupled with the rotor 25 of the first electric motor 20 andthe carrier CR0 is coupled with the output shaft 12. The power splittingplanetary gear 21 constructed as described above splits the motive powerinputted to the ring gear R0 via the input shaft 10 to the firstelectric motor 20 via the sun gear S0 and to the output shaft 12 via thecarrier CR0 based on the control on the revolution of the first electricmotor 20. It is noted that the power split to the first electric motor20 is used for generating electricity and the power split to the outputshaft 12 is used for driving the vehicle 1.

In the hybrid driving unit 7D shown in FIG. 13, all of the four devicesof the transmission 22, the second electric motor 23, the first electricmotor 20 and the power splitting planetary gear 21 are disposed on theinput shaft 10. These are coupled each other as follows as shown in thefigure.

The input shaft 10 is coupled with the ring gear (first rotary element)R0 of the power splitting planetary gear 21 through the inner peripheralside of the transmission 22, the second electric motor 23, the firstelectric motor 20 and the power splitting planetary gear 21 and throughthe rear side of the power splitting planetary gear 21. The output shaft12 is coupled with the front side of the carrier (third rotary element)CR0 of the power splitting planetary gear 21 through the outerperipheral side of the power splitting planetary gear 21 and between thepower splitting planetary gear 21 and the first electric motor 20. Therotor 25 of the first electric motor 20 is coupled with the sun gear(second rotary element) S0 of the power splitting planetary gear 21.Then, the rotor 29 of the second electric motor 23 is coupled with thesun gear S1 through the inner peripheral side of the sun gear S2.

In the hybrid driving unit 7D constructed as described above, the motivepower inputted to the input shaft 10 is inputted to the ring gear R0 ofthe power splitting planetary gear 21 to be split (divided) to the sungear S0 and the carrier CR0 as shown in the skeleton view of FIG. 13.Among them, the motive power split to the sun gear S0 is inputted to therotor 25 of the first electric motor 20 to be used to generateelectricity. The electricity thus generated is charged to the HV batteryvia the inverter. The second electric motor 23 receives the electricitysupplied from the HV battery via the inverter and drives the outputshaft 12 via the transmission 22. That is, the motive power from theinternal combustion engine 5 is combined with the power from the secondelectric motor 23 and is outputted to the output shaft 12. It is notedthat because the transmission 22 is arranged so as to be capable ofswitching between the high and low states as described above, powercorresponding to the high or low state is outputted to the output shaft12.

Since the first electric motor 20 and the second electric motor 23 aredisposed adjacently to each other on the axis 13 as shown in FIG. 13 inthe present embodiment, the parts of the case storing these first andsecond electric motors 20 and 23 may be combined, thus facilitating theaccommodation in producing the unit in series. It also brings about sucheffects that a number of parts and, hence the cost, may be reduced, theaccuracy for supporting the two electric motors 20 and 23 may beimproved, the length of power cables of the two electric motors 20 and23 may be almost equalized regardless of the position of the controllerfor controlling them, the length of the cable may be minimized when theinverter is disposed within an engine room on the front side of thevehicle, thus minimizing the loss of electricity, and others.

It is noted that although the hydraulic actuators have been used for thefirst and second brakes B1 and B2 explained in the first through fourthembodiments described above, not only the hydraulic actuators, but alsoother actuators such as an electric actuator using a ball screwmechanism and an electric motor may be used instead. Still more, notonly the friction engaging elements, but also an engaging type elementsmay be used.

Further, it is needless to say that not only the transmission 22described above in the embodiments, but also an automatic transmissionhaving two, three or more stages, an automatic transmission having anover-drive stage (O/D) or a continuously variable transmission (CVT) maybe used. Still more, the output of the transmission 22 may be outputtednot only to the output shaft 12 but also to any part of a powertransmission system from the output shaft 12 to the driving wheels.

INDUSTRICAL APPLICABILITY

The inventive hybrid driving unit described above is applicable tovehicles and is suitably applicable to FR vehicles.

1. A hybrid driving unit, comprising: an input shaft for inputtingmotive power from an internal combustion engine; an output shaftdisposed on an axis in line with said input shaft and interlocked withdriving wheels; a first electric motor disposed on the axis andcomprising a stator and a rotor; a power splitting planetary geardisposed on the axis and comprising a first rotary element coupled withsaid input shaft, a second rotary element coupled with the rotor of saidfirst electric motor and a third rotary element coupled with said outputshaft; a second electric motor disposed on the axis and comprising astator and a rotor; and a transmission disposed on the axis and shiftingand transmitting revolution of the rotor of said second electric motorto said output shaft; said hybrid driving unit being characterized inthat: said first electric motor, said power splitting planetary gear,said second electric motor and said transmission are stored in a casingmember while being disposed in line on the axis; the stators of saidfirst and second electric motors are fixed to said casing member; andsaid first electric motor, said power splitting planetary gear, saidsecond electric motor and said transmission are disposed on the axis sothat said first electric motor and said second electric motor adjoineach other on the axis.
 2. The hybrid driving unit as set forth in claim1, characterized in that said casing member comprises a plurality ofconnected partial cases in a body in the axial direction and said firstand second electric motors are stored in one of said partial cases. 3.The hybrid driving unit as set forth in claim 2, characterized in thatsaid casing member comprises a joint section of said partial cases atthe part where said transmission and said power splitting planetary gearare stored.
 4. The hybrid driving unit as set forth in claim 2,characterized in that said partial case storing said first and secondelectric motors is divided into a front part close to said internalcombustion engine and to a rear part by a partition and the radial sizeof a motor storage section of the front part is larger than that of amotor storage section of the rear part.
 5. The hybrid driving unit asset forth in claim 4, characterized in that partitions extending fromsaid casing member support the both sides of the rotors of said firstand second electric motors through an intermediary of bearing members;wherein one of said partitions is located between said first electricmotor and said second electric motor and comprises bearing memberssupporting the rotors of said first and second electric motors,respectively.
 6. The hybrid driving unit as set forth in claim 5,characterized in that said input shaft is supported by the innerperipheral face of the rotor of said first electric motor through anintermediary of bearing members provided on the outer peripheral face ofsaid input shaft.
 7. The hybrid driving unit as set forth in claim 1,characterized in that said first electric motor, said second electricmotor, said transmission and said power splitting planetary gear aredisposed in order from the side closer to said internal combustionengine.
 8. The hybrid driving unit as set forth in claim 7,characterized in that said input shaft is coupled with said first rotaryelement through the inner periphery of said first electric motor, saidsecond electric motor and said transmission, and an output element ofsaid transmission is coupled with said output shaft through the outerperiphery of said power splitting planetary gear.
 9. The hybrid drivingunit as set forth in claim 8, characterized in that said power splittingplanetary gear comprises a single pinion planetary gear; said inputshaft is coupled with a rear side of a carrier of said single pinionplanetary gear through the inner periphery of said power splittingplanetary gear; said output shaft is coupled with said output element ofsaid transmission via a ring gear of said single pinion planetary gear;and the rotor of said first electric motor is coupled with a sun gear ofsaid single pinion planetary gear through the inner periphery of saidsecond electric motor and said transmission.
 10. The hybrid driving unitas set forth in claim 8, characterized in that said power splittingplanetary gear comprises a single pinion planetary gear; said inputshaft is coupled with the transmission side of a carrier of said singlepinion planetary gear; said output shaft is coupled with a sun gear ofsaid single pinion planetary gear and with the output element of saidtransmission through the outer periphery of said power splittingplanetary gear; and the rotor of said first electric motor is coupledwith a ring gear of said single pinion planetary gear through the innerperiphery of said second electric motor and said transmission.
 11. Thehybrid driving unit as set forth in claim 8, characterized in that saidpower splitting planetary gear comprises a double pinion planetary gear;said input shaft is coupled with a ring gear of said double pinionplanetary gear through the rear side of said power splitting planetarygear; said output shaft is coupled with the transmission side of acarrier of said double pinion planetary gear through the outer peripheryof said power splitting planetary gear and with the output element ofsaid transmission; and the rotor of said first electric motor is coupledwith a sun gear of said double pinion planetary gear through the innerperiphery of said second electric motor and said transmission.
 12. Thehybrid driving unit as set forth in claim 8, characterized in that saidpower splitting planetary gear the comprises a double pinion planetarygear; said input shaft is coupled with the ring gear of said doublepinion planetary gear through the rear side of said power splittingplanetary gear; said output shaft is coupled with the sun gear of saiddouble pinion planetary gear and with the output element of saidtransmission through the outer periphery of said power splittingplanetary gear and between said power splitting planetary gear and saidtransmission; and the rotor of said first electric motor is coupled withthe rear side of the carrier of said double pinion planetary gearthrough the inner periphery of said second electric motor and saidtransmission.
 13. The hybrid driving unit as set forth in claim 1,characterized in that said first electric motor, said second electricmotor, said power splitting planetary gear and said transmission aredisposed in order from the side closer to said internal combustionengine.
 14. The hybrid driving unit as set forth in claim 13,characterized in that said input shaft is coupled with the first rotaryelement through the inner periphery of said first electric motor andsaid second electric motor; the rotor of said second electric motor iscoupled with said transmission through the outer periphery of said powersplitting planetary gear; and said output shaft is coupled with anoutput element of said transmission and with the third rotary elementthrough the inner periphery of said transmission.
 15. The hybrid drivingunit as set forth in claim 14, characterized in that said powersplitting planetary gear comprises a single pinion planetary gear; saidinput shaft is coupled with the transmission side of a carrier of saidsingle pinion planetary gear through the inner periphery of said powersplitting planetary gear; said output shaft is coupled with the outputelement of said transmission and with a ring gear of said single pinionplanetary gear through between said power splitting planetary gear andsaid transmission; the rotor of said first electric motor is coupledwith a sun gear of said single pinion planetary gear through the innerperiphery of said second electric motor; and the rotor of said secondelectric motor is coupled with an input element of said transmissionthrough the outer periphery of said power splitting planetary gear. 16.The hybrid driving unit as set forth in claim 14, characterized in thatsaid power splitting planetary comprises a single pinion planetary gear;said input shaft is coupled with the second electric motor side of acarrier of said single pinion planetary gear; said output shaft iscoupled with the output element of said transmission and with a sun gearof said single pinion planetary gear; the rotor of said first electricmotor is coupled with the ring gear of said single pinion planetary gearthrough between said second electric motor and said power splittingplanetary gear; and the rotor of said second electric motor is coupledwith an input element of said transmission through the outer peripheryof said power splitting planetary gear.
 17. The hybrid driving unit asset forth in claim 14, characterized in that said power splittingplanetary gear comprises a double pinion planetary gear; said inputshaft is coupled with a ring gear of said double pinion planetary gearthrough between said power splitting planetary gear and saidtransmission; said output shaft is coupled with the output element ofsaid transmission and with a sun gear of said double pinion planetarygear through between said power splitting planetary gear and saidtransmission, through the outer periphery of said power splittingplanetary gear and through between said power splitting planetary gearand said second electric motor; the rotor of said first electric motoris coupled with the transmission side of the carrier of said doublepinion planetary gear through the inner peripheral side of said secondelectric motor and through between said power splitting planetary gearand said transmission; and the rotor of said second electric motor iscoupled with an input element of said transmission through the outerperiphery of said power splitting planetary gear.
 18. The hybrid drivingunit as set forth in claim 14, characterized in that said powersplitting planetary comprises a double pinion planetary gear; said inputshaft is coupled with a carrier of said double pinion planetary gearthrough between said power splitting planetary gear and saidtransmission; said output shaft is coupled with the output element ofsaid transmission and with the ring gear of said double pinion planetarygear through between said power splitting planetary gear and saidtransmission; the rotor of said first electric motor is coupled with thesun gear of said double pinion planetary gear through the innerperipheral side of said second electric motor; and the rotor of saidsecond electric motor is coupled with the input element of saidtransmission through the outer peripheral side of said power splittingplanetary gear.
 19. The hybrid driving unit as set forth in claim 1,characterized in that said transmissions comprises a planetary gearunit.
 20. The hybrid driving unit as set forth in claim 19,characterized in that said transmission comprises at least four shiftingelements, the first shifting element is coupled with the rotor of saidsecond electric motor, the second shifting element is coupled with saidoutput shaft, and said transmission comprises braking elements which arecapable of fixing the third and fourth shifting elements to said casingmember, respectively.
 21. The hybrid driving unit as set forth in claim19, characterized in that said planetary gear of said transmissioncomprises a Ravigneaux type planetary gear and a carrier of saidRavigneaux type planetary gear is coupled with said output shaft. 22.The hybrid driving unit as set forth in claim 1, characterized in thatsaid power splitting planetary gear, said first electric motor, saidsecond electric motor and said transmission are disposed in order fromthe side closer to said internal combustion engine.
 23. The hybriddriving unit as set forth in claim 22, characterized in that said inputshaft is coupled with the first rotary element, and an output element ofsaid transmission is coupled with said output shaft disposed through theinner periphery of said power splitting planetary gear, said firstelectric motor, said second electric motor and said transmission. 24.The hybrid driving unit as set forth in anyone of claims 1 through 6,characterized in that said transmission, said second electric motor,said first electric motor and said power splitting planetary gear aredisposed in order from the side closer to said internal combustionengine.
 25. The hybrid driving unit as set forth in claim 24,characterized in that said input shaft is coupled with the first rotaryelement through the inner periphery of said transmission, said secondelectric motor, said first electric motor and said power splittingplanetary gear, and the output element of said transmission is coupledwith said output shaft through between said input shaft and the innerperiphery of said transmission, said second electric motor, said firstelectric motor and said power splitting planetary gear.
 26. A vehiclecomprising an internal combustion engine, hybrid driving means and rearwheels as driving wheels to which driving force is transmitted from saidhybrid driving means; said vehicle being characterized in that: saidhybrid driving means is the hybrid driving unit as set forth in anyoneof claim 1; and said hybrid driving unit is arranged such that saidinput shaft is coupled with an output shaft of said internal combustionengine, a propeller shaft is coupled with said output shaft of saidinternal combustion engine, and said output shaft of said internalcombustion engine, said input shaft, said output shaft of said hybriddriving unit and said propeller shaft are disposed approximately on oneand the same axis.